Zeus
* Zeus laneing against Ember is going to be punished with Sleight of Fist due to his low health pool
* Zeus's chip damage from 
Arc Lightning and other spells is nullified from Ember's Flame Guard.
Additional:
* Ember Spirit has a built-in antimagic shield, and Zeus has nothing but this magical damage, because of this, their confrontation on the center line can turn out to be sad for Zeus. If on such a line Ember Spirit will finish off all creeps under its 
Flame Guard, and Zeus with the help of Arc Lightning, then eventually Zeus will lose mana faster, and will be forced to look for ways to replenish it
* Ember Spirit can interrupt Zeus with his "jumping" abilities, the fact is that Zeus deals damage from his abilities directly, while Ember Spirit disappears for milliseconds from the battlefield when flying during the 
Sleight of Fist action or when flying into 
Fire Remnant
Io
* Heroes with either magical, physical or pure damage burst: 
Bane, 
Ember Spirit, 
Leshrac, 
Lina, 
Luna, 
Nyx Assassin, 
Phantom Assassin, 
Skywrath Mage, 
Tinker, 
Ursa, 
Void Spirit.
Zeus
* As a spellcaster, silences will nullify him entirely. Some notable examples are 
Death Prophet, 
Drow Ranger, 
Bloodseeker, 
Disruptor and many others.
* 
Doom, as usual, fits this description nicely.
Io
* 
Thirst allows Bloodseeker to see where Io relocated to, should either Io or the tethered hero have low health.
* 
Rupture forces Io to stay in place, preventing it from using the Tether bonus movement speed to escape.
Zeus
* As a spellcaster, silences will nullify him entirely. Some notable examples are Death Prophet, Drow Ranger, Bloodseeker, Disruptor and many others.
* Doom, as usual, fits this description nicely.
Io
* Disruptor can always Glimpse back Io or his target after he 
Relocated nearby.
* Even better, thanks to the indicator on the ground, you can even preemptively drop Static Storm and Kinetic Field on the spot they will relocate to.
* Thunder Strike and Glimpse are also good tools to bring back an Io that 
Tethered away in the fog of war.
Additional:
* 
Glimpse directly negates Relocate.
* 
Kinetic Field prevents Io from escaping with Tether.
* 
Static Storm can silence and damage both, Io and it's tethered target. And it can also mute both, Io and it's tethered target when upgraded with 
Aghanim's Scepter.
Zeus
* Heroes with long range abilities are also able to touch Zeus, such as 
Clockwerk, 
Kunkka, 
Puck, Skywrath Mage, 
Spirit Breaker, 
Tusk and others.
Io
* 
Charge of Darkness can be used to escape or counter-initiate against a Relocate gank.
* 
Greater Bash and 
Nether Strike is devastating due to Io's low armor, and can even knock it away from his Tethered target.
Zeus
* Chaos Knight's high health pool makes him resistant to Zeus' burst damage. 
Phantasm can dispel 
Veil of Discord, a typical item purchased by Zeus.
* Zeus is easily overwhelmed by Chaos Knight's strong illusions, as Arc Lightning is not enough to kill them fast enough to have any impact.
* Zeus' low base armor makes him extremely vulnerable to Chaos Knight's high damage output and armor reduction.
Io
* Heroes with both illusions and summons, for Io has nothing to deal with multiple enemies at once outside from Spirits's weak area-of-effect: 
Beastmaster, 
Broodmother, 
Chaos Knight, 
Lycan, 
Naga Siren, 
Nature's Prophet, 
Phantom Lancer, 
Shadow Shaman, 
Terrorblade, 
Visage, 
Warlock, 
Wraith King.
Zeus
* Heroes with a lot of burst damage, especially those who rely on casting spells: Lina, 
Zeus.
Io
* Heroes that are hard to gank: 
Axe, Death Prophet, Phantom Lancer, 
Slark, 
Centaur Warrunner, 
Bristleback, 
Medusa, 
Mars.
Zeus
* Visage can quickly kill heroes with low to medium base armor and no innate escape mechanism. Examples include 
Alchemist, 
Crystal Maiden and Zeus.
Io
* Heroes with both illusions and summons, for Io has nothing to deal with multiple enemies at once outside from Spirits's weak area-of-effect: Beastmaster, Broodmother, Chaos Knight, Lycan, Naga Siren, Nature's Prophet, Phantom Lancer, Shadow Shaman, Terrorblade, Visage, Warlock, Wraith King.
Zeus
* Heroes who have most or all their abilities (damage or disable) unable to pierce spell immunity: 
Keeper of the Light, Lina, 
Lion, Zeus.
Additional:
* 
Rage is very useful against Zeus, as it negates magic damage and provides spell immunity. In addition, the increased attack speed can tear Zeus apart in combination with 
Open Wounds.
* Lifestealer can avoid Thundergod's Wrath with 
Infest.
Io
* Heroes that can easily bypass Io's allies to get to Io: 
Riki, Tusk, 
Clinkz, 
Sniper, Slark, Phantom Assassin, Void Spirit, 
Storm Spirit, Ember Spirit, 
Earth Spirit, Spirit Breaker, 
Lifestealer.
Zeus
* Heroes that depend on disrupting fights with ability combos or big ultimate abilities are vulnerable to the long stun of Fiend's Grip: Disruptor, Death Prophet, 
Enigma, 
Faceless Void, 
Invoker, 
Lich, 
Magnus, Mars, Medusa, 
Outworld Destroyer, 
Phoenix, Puck, 
Queen of Pain, 
Shadow Fiend, 
Treant Protector, 
Underlord, 
Winter Wyvern, 
Witch Doctor, Zeus.
Io
* Heroes with either magical, physical or pure damage burst: Bane, Ember Spirit, Leshrac, Lina, Luna, Nyx Assassin, Phantom Assassin, Skywrath Mage, Tinker, Ursa, Void Spirit.
Zeus
* Heroes with long range abilities are also able to touch Zeus, such as Clockwerk, Kunkka, Puck, Skywrath Mage, Spirit Breaker, Tusk and others.
Io
* Heroes with either magical, physical or pure damage burst: Bane, Ember Spirit, Leshrac, Lina, Luna, Nyx Assassin, Phantom Assassin, Skywrath Mage, Tinker, Ursa, Void Spirit.
Zeus
* Spirit Siphon does a lot of magical damage, especially in the early game. This allows her to demolish low health heroes such as Zeus, 
Pugna, especially when combined with her other spells.
Io
* Heroes that are hard to gank: Axe, Death Prophet, Phantom Lancer, Slark, Centaur Warrunner, Bristleback, Medusa, Mars.
Zeus
* Zeus can deal a huge amount of damage, but he lacks defensive abilities, such as good mobility or resistance. Due to that, he doesn't like to be touched by any means. Heroes with higher damage output and good mobility will often get easily near Zeus and trade damage (eventually causing Zeus's downfall). Such Heroes include: Lycan, Slark, Storm Spirit, 
Spectre and others.
Io
* Heroes that can easily bypass Io's allies to get to Io: Riki, Tusk, Clinkz, Sniper, Slark, Phantom Assassin, Void Spirit, Storm Spirit, Ember Spirit, Earth Spirit, Spirit Breaker, Lifestealer.
Zeus
* Once you get a 
Black King Bar, squishy spellcasters like Zeus, Skywrath Mage and others will be probably easy to deal with.
Io
* Heroes with both illusions and summons, for Io has nothing to deal with multiple enemies at once outside from Spirits's weak area-of-effect: Beastmaster, Broodmother, Chaos Knight, Lycan, Naga Siren, Nature's Prophet, Phantom Lancer, Shadow Shaman, Terrorblade, Visage, Warlock, Wraith King.
Zeus
* Heroes with long range abilities are also able to touch Zeus, such as Clockwerk, Kunkka, Puck, Skywrath Mage, Spirit Breaker, Tusk and others.
Io
* Heroes that can easily bypass Io's allies to get to Io: Riki, Tusk, Clinkz, Sniper, Slark, Phantom Assassin, Void Spirit, Storm Spirit, Ember Spirit, Earth Spirit, Spirit Breaker, Lifestealer.
Io
* 
Living Armor and 
Leech Seed can be used to save a hero from a Relocate gank.
* 
Overgrowth can be used to cancel escape attempts with Relocate.
* Once Treant Protector buys Aghanim's Scepter, he will gain access to 
Eyes in the Forest, that will allow him to enchant a tree which will grant him unobstructed vision in that location, allowing him to keep his allies alerted on Io and his Tethered's attempts to gank them, and which can also allow Overgrowth to damage them and root them if they are within a 800 radius of an tree affected by Eyes in the Forest.
Zeus
* Marci on the midlane will win the laning phase against Zeus almost every time, as her powerspike at level 6 will decimate Zeus' low health pool and force him to stay far back.
* Even before level 6, Dispose and Sidekick can easily take half of Zeus' health if he is in range of Dispose.
Zeus
* 
Corrosive Skin severely reduces Zeus's damage output throughout the game.
* During the laning stage, Viper can abuse Zeus' reliance on spells by hugging the creep wave. Zeus will take constant damage over time from Corrosive Skin unless he drives Viper from the lane or returns to farming in his absence.
* Prior to buying 
Blink Dagger or 
Force Staff, Zeus is fragile and possesses low mobility. Any of Viper's numerous slows can set up an easy kill.
Additional:
* Corrosive Skin counters Zeus in lane by canceling the effects of 
Clarity as Zeus relies on Arc Lightning to farm and secure last hits.
* Corrosive Skin also increases Viper's magic resistance to shrug off Zeus's magical nukes.
* 
Nethertoxin breaks Static Field.
* Due to Zeus' poor mobility, 
Viper Strike will cripple Zeus and will allow Viper and his teammates to land a lot of attacks.
Io
* Fireblast is a good tool to interrupt Io during its escapes through Tether.
* Ignite can be one of the few spells with enough total damage to out-trade the sustained healing Io provides for its fellow laner.
* However, picking other supports that focus less on the laning phase is generally a better choice against Io.
Io
* 
Phantom Strike allows Phantom Assassin jump directly to Io.
* 
Coup de Grace can make a short work of Io's low health and armor.
Io
* Io is a hero who needs to be close to it's tethered target to make it effective, and that's where Leshrac gets the advantage thanks to many of his area-of-effect abilities.
* 
Lightning Storm will usually hit both Io and its tethered target since both will be close enough for the lightning to jump.
* 
Diabolic Edict and 
Pulse Nova hit all units near Leshrac, meaning he can do colossal damage to both, Io and its tethered target.
Additional:
* Lightning Storm will usually hit both Io and his Tethered target since both will be close enough for the lightning to jump. It can then be followed up by Split Earth.
* Diabolic Edict and Pulse Nova hit all units near Leshrac, meaning he can do colossal damage to Io and his Tethered target.
Io
* Ice Blast prevents Io from healing an ally with Tether and prevents healing from 
Overcharge
* Io is a common 
Mekansm builder which is useless if he is affected by Ice Blast.
Additional:
* 
Ice Blast prevents Io from healing the target.
* Ancient Apparition can easily harass Io on lane with 
Chilling Touch due to it's high range and damage. This can get even worse if Ancient Apparition buys Aghanim's Scepter and combines it with items that can give him bonus attack damage and attack speed.
* Chilling Touch combined with 
Ice Vortex makes it nearly impossible for Io to escape from 
Cold Feet. Ice Vortex can also make Io and it's tethered target more vulnerable to Ancient Apparition and his allies's magical damage.
Io
* Jakiro's area-of-effect ability arsenal allows him to affect multiple heroes at once, giving Io difficulties in saving them as he can only heal one hero at a time with Tether.
* 
Ice Path can be used to cancel both, Tether and Relocate.
* Jakiro commonly buys 
Rod of Atos that can be used to cancel Relocate, prevent Io in escaping with Tether and make Io easy target for Ice Path and 
Macropyre.
Additional:
* Jakiro's area-of-effect ability arsenal allows him to affect multiple heroes at once, giving Io difficulties in saving them as he can only heal one hero at a time with Tether.
* Ice Path can be used to cancel both, Tether and Relocate.
* Jakiro commonly buys Rod of Atos that can be used to cancel Relocate, prevent Io in escaping with Tether and make Io easy target for Ice Path and Macropyre.
Zeus
* Zeus' main source of damage is his low cooldown, high damage spells - meaning Last Word and Global Silence will pretty much take him out of the game for the duration.
* Zeus likes to spam his abilities, which makes him vulnerable to Arcane Curse.
* If Zeus dies near Silencer, he will begin to lose intelligence, reducing his mana pool, mana regen, and attack damage. Furthermore, if the game is long and Zeus dies often, the intelligence losses will also reduce his spell damage.
Additional:
* Silencer's 
Global Silence will render Zeus useless for 6 seconds in a team fight.
* 
Arcane Curse will punish Zeus for casting spells, which can cause continuous damage to him should he continue to cast spells.
* 
Last Word can silence Zeus and prevent him from spamming his spells.
* Silencer often builds 
Orchid Malevolence (or 
Bloodthorn) which can be used on spell casters like Zeus, forcing him to invest in a 
Linken's Sphere.
Zeus
* Even though Pugna's low HP means that he can be quickly burst down, his 
Nether Ward heavily punishes casters whose spells cost a lot of mana, like Zeus. Casting 4 of his active spells, including Nimbus, close to an enhanced level 4 Nether Ward, can make the ward deal up to 1750 magical damage.
* 
Decrepify can further increase the damage dealt by Nether Ward upon Zeus. However, if used on Pugna himself or on one of his allies, it will amplify the damage done by Zeus' abilities.
Zeus
* 
Time Dilation can limit Zeus to casting his abilities only once in a fight, effectively serving as a 6/8/10/12 second silence.
* 
Time Walk negates Zeus's burst damage.
* 
Chronosphere makes Zeus the best target for Void because of his low mobility.
Zeus
* Zeus almost exclusively relies on magical damage, which is heavily reduced by Counterspell.
* Zeus' complete lack of mobility makes him very easy for Anti-Mage to chase down with Blink.
* Zeus likes to stand in the back during team fights, but Anti-Mage can easily Blink to close the distance.
Additional:
* Anti-Mage can burn mana, which is a big problem for a spellcaster like Zeus that heavily relies on it.
* 
Counterspell decreases magical damage taken from Zeus.
* Zeus' high intelligence and mana pool makes him a perfect target for 
Mana Void.
Zeus
* Huskar's Burning Spears chip through his low health pool quickly.Consequently, he is forced to either invest on health regen or abandon the lane.
* Reliant on magic damage, there is little he can do against Huskar.
* Huskar will usually kill him if he gets Life Break off,given Zeus' poor mobility.
Io
* 
Quill Spray is very effective against Io, as it has very low armor and has to stay close to the fight to not break its Tether.
Io
* Heroes that are hard to gank: Axe, Death Prophet, Phantom Lancer, Slark, Centaur Warrunner, Bristleback, Medusa, Mars.
Zeus
* Heroes with low mobility that rely on spells: Zeus, Lina, Crystal Maiden.
Io
* Heroes with both illusions and summons, for Io has nothing to deal with multiple enemies at once outside from Spirits's weak area-of-effect: Beastmaster, Broodmother, Chaos Knight, Lycan, Naga Siren, Nature's Prophet, Phantom Lancer, Shadow Shaman, Terrorblade, Visage, Warlock, Wraith King.
Io
* Heroes with both illusions and summons, for Io has nothing to deal with multiple enemies at once outside from Spirits's weak area-of-effect: Beastmaster, Broodmother, Chaos Knight, Lycan, Naga Siren, Nature's Prophet, Phantom Lancer, Shadow Shaman, Terrorblade, Visage, Warlock, Wraith King.
Zeus
* Heroes who cannot prevent Sven from killing supports will always be at a disadvantage in fights such as Lina, Slark and Zeus.
Io
* Heroes with both illusions and summons, for Io has nothing to deal with multiple enemies at once outside from Spirits's weak area-of-effect: Beastmaster, Broodmother, Chaos Knight, Lycan, Naga Siren, Nature's Prophet, Phantom Lancer, Shadow Shaman, Terrorblade, Visage, Warlock, Wraith King.
Io
* Heroes that are hard to gank: Axe, Death Prophet, Phantom Lancer, Slark, Centaur Warrunner, Bristleback, Medusa, Mars.
Zeus
* Heroes with long range abilities are also able to touch Zeus, such as Clockwerk, Kunkka, Puck, Skywrath Mage, Spirit Breaker, Tusk and others.
Io
* Heroes with either magical, physical or pure damage burst: Bane, Ember Spirit, Leshrac, Lina, Luna, Nyx Assassin, Phantom Assassin, Skywrath Mage, Tinker, Ursa, Void Spirit.
Io
* Heroes with both illusions and summons, for Io has nothing to deal with multiple enemies at once outside from Spirits's weak area-of-effect: Beastmaster, Broodmother, Chaos Knight, Lycan, Naga Siren, Nature's Prophet, Phantom Lancer, Shadow Shaman, Terrorblade, Visage, Warlock, Wraith King.
Zeus
* Heroes with long range abilities are also able to touch Zeus, such as Clockwerk, Kunkka, Puck, Skywrath Mage, Spirit Breaker, Tusk and others.
Io
* Squishy heroes (
Io, Crystal Maiden, Lina...), as Earth Spirit can deal tons of damage with Magnetize.
Io
* Heroes with either magical, physical or pure damage burst: Bane, Ember Spirit, Leshrac, Lina, Luna, Nyx Assassin, Phantom Assassin, Skywrath Mage, Tinker, Ursa, Void Spirit.
Io
* Heroes with either magical, physical or pure damage burst: Bane, Ember Spirit, Leshrac, Lina, Luna, Nyx Assassin, Phantom Assassin, Skywrath Mage, Tinker, Ursa, Void Spirit.
Io
* Heroes whose abilities can affect multiple enemies at once: 
Dawnbreaker, Ember Spirit, Lina, Luna, 
Jakiro, Leshrac, Invoker, 
Muerta, 
Dazzle.
Zeus
* Zeus can deal a huge amount of damage, but he lacks defensive abilities, such as good mobility or resistance. Due to that, he doesn't like to be touched by any means. Heroes with higher damage output and good mobility will often get easily near Zeus and trade damage (eventually causing Zeus's downfall). Such Heroes include: Lycan, Slark, Storm Spirit, Spectre and others.
Io
* Heroes that can easily bypass Io's allies to get to Io: Riki, Tusk, Clinkz, Sniper, Slark, Phantom Assassin, Void Spirit, Storm Spirit, Ember Spirit, Earth Spirit, Spirit Breaker, Lifestealer.
Zeus
* Heroes with heavy magical nukes will take advantage of Slark's poor HP or force him to use Shadow Dance early: Lina, Lion, Zeus
Zeus
* Heroes with long range abilities are also able to touch Zeus, such as Clockwerk, Kunkka, Puck, Skywrath Mage, Spirit Breaker, Tusk and others.
Io
* Heroes with the ability to heal allies will not be able to heal heroes affected by Doom: 
Chen, Dazzle, Io, 
Oracle, 
Omniknight, Witch Doctor, Winter Wyvern, 
Abaddon, etc.
Zeus
* Heroes with summons that are destroyed by a fixed number of attacks: 
Undying's 
Tombstone, 
Gyrocopter's 
Homing Missile, and Zeus's 
Nimbus.
Io
* Heroes with both illusions and summons, for Io has nothing to deal with multiple enemies at once outside from Spirits's weak area-of-effect: Beastmaster, Broodmother, Chaos Knight, Lycan, Naga Siren, Nature's Prophet, Phantom Lancer, Shadow Shaman, Terrorblade, Visage, Warlock, Wraith King.
Io
* 
Cold Embrace can render the extra attack speed from Overcharge meaningless.
* 
Splinter Blast and 
Winter's Curse are very affective against Io, as it has to stay close to his Tethered target.
Zeus
* Heavy nukers will do well against Cold Embrace (Lina, Zeus etc).
Additional:
* Any ally that Winter Wyvern tries to save with Cold Embrace can still be damaged by all of Zeus's spells.
* If Winter Wyvern tries to juke vision by flying up a cliff or in the trees, Zeus can gain vision there with Lightning Bolt or Thundergod's Wrath.
* If Zeus is forced to attack an ally by Winter's Curse, his unimpressive attack damage and attack speed means they won't be hurt much by him. Zeus will also stay near the back of fights away from his allies, making a deadly Curse less likely.
Zeus
* None of Zeus's abilities can damage a Juggernaut in 
Blade Fury.
* Zeus's short attack range makes it difficult for him to target a well-placed 
Healing Ward. His frequent use of Arc Lightning will have almost no effect on allies being healed by Juggernaut.
* Zeus has no way to defend himself, even if Juggernaut cannot use Blade Fury. He can be easily taken out if cornered, sometimes even without 
Omnislash.
Additional:
* Blade Fury negates all magical damage from Zeus.
* Omnislash can easily take down Zeus. However, be aware that most players will get a 
Eul's Scepter of Divinity or a 
Ghost Scepter against Juggernaut.
Io
* Heroes with abilities that can save teammates are also effective such as 
Shadow Demon, Dazzle, Oracle, Bane, Pugna, Tusk, Winter Wyvern, Io, Underlord, Treant Protector and Keeper of the Light.
Zeus
* Zeus burst damage can be reduced by 
Dispersion and reflect some of the damage back to Zeus himself.
* Zeus has low mobility and stays in backlines, 
Spectral Dagger or 
Haunt can easily catch him as he has no escape mechanism.
* Since Zeus has low HP, Spectral Dagger and 
Desolate will quickly tear Zeus down when he's alone.
Zeus
* Zeus is good against heroes that juke in trees or up cliffs, like 
Batrider, 
Monkey King, Spectre, and Tinker, by providing vision in any area with Lightning Bolt, or guaranteeing vision on enemies with Thundergod's Wrath.
Io
* 
Poison Touch allows Dazzle to harass both, Io and it's tethered target on lane. 
Aghanim's Shard upgraded Poison Touch can also hex both, Io and it's tethered target, preventing them from escaping with Relocate, and also disarming them, silencing them, muting them and rendering them helpless against Dazzle and his allies.
* Io's damage output is one of the weakest, therefore Dazzle will have plenty of time to save an ally with 
Shallow Grave from gank by Io and it's tethered target.
* 
Shadow Wave will always hit both, Io and it's tethered target if they are near the ally Dazzle uses Shadow Wave on, while healing Dazzle's allies near them. Aghanim's Scepter upgraded Shadow Wave can bounce on both, Io and it's tethered target, causing them both to take damage and to be attacked by Dazzle. And unlike Io who doesn't get healed while using Tether, Shadow Wave will always heal Dazzle no matter on which of his allies he uses it on.
* 
Bad Juju will cause both, Io and it's tethered target to lose armor every time Dazzle casts a spell while strengthening armor of Dazzle's allies.
Additional:
* Poison Touch allows Dazzle to harass both, Io and it's Tethered target on lane. Aghanim's Shard upgraded Poison Touch can also hex both, Io and it's Tethered target, preventing them from escaping with Relocate, and also disarming them, silencing them, muting them and rendering them helpless against Dazzle and his allies.
* Io's damage output is one of the weakest, therefore Dazzle will have plenty of time to save an ally with Shallow Grave from gank by Io and it's Tethered target.
* Shadow Wave will always hit both, Io and it's Tethered target if they are near the ally Dazzle uses Shadow Wave on, while healing Dazzle's allies near them. Aghanim's Scepter upgraded Shadow Wave allows Dazzle Shadow Wave directly on Io and it's Tethered target which can also bounce on both, Io and it's tethered target, causing them both to take damage and to be attacked by Dazzle. And unlike Io who doesn't get healed while using Tether, Shadow Wave will always heal Dazzle no matter on which of his allies he uses it on.
* Bad Juju will cause both, Io and it's tethered target to lose armor every time Dazzle casts a spell while strengthening armor of Dazzle's allies.
Zeus
* Some heroes with extreme range, like Zeus, Invoker or Clockwerk, can snipe your allies from anywhere after your Grave has expired.
Io
* 
Take Aim and 
Assassinate allow Sniper to reach Io even if it stays in the backline.
Io
* Heroes with high mobility can approach Sniper: 
Anti-Mage, Earth Spirit, Io, Nature's Prophet, 
Pangolier, Puck, Queen of Pain and most notably Riki.
Io
* Homing Missile can be used to cancel escape attempts with Relocate.
* 
Flak Cannon allows Gyrocopter to attack both, Io and his Tethered target, especially when upgraded with Aghanim's Scepter.
* 
Rocket Barrage and 
Call Down allow Gyrocopter to deal serious damage to both Io and his Tethered target.
Additional:
* Homing Missile can be used to cancel escape attempts with Relocate.
* Flak Cannon allows Gyrocopter to attack both, Io and his Tethered target, especially when upgraded with Aghanim's Scepter.
* Rocket Barrage and Call Down allow Gyrocopter to deal serious damage to both Io and his Tethered target.
Zeus
* Heroes with high magical burst damage will kill Gyrocopter before he gets to do much: Lina, Lion, Zeus
Io
* Soulbind can target both Io and its Tethered ally, allowing Grimstroke and his team to target both with single target spells. Should Io try to Relocate, Phantom's Embrace can stop its channel to prevent escape.
Additional:
* Grimstroke can catch Io and his Tethered ally easily with 
Soulbind as Io has a tendency to Tether himself with an ally frequently, which also makes them easier targets for Soulbind.
* Io is highly vulnerable to disables. Hence, Grimstroke's 
Phantom's Embrace is a great ability to hinder Io's potential.
Zeus
* Heroes with powerful spammable abilities will prove problematic for Grimstroke as Ink Swell does not protect him from them: Zeus, Skywrath Mage, Tinker, Lina
Zeus
* Although 
Lightning Bolt and 
Thundergod's Wrath can reveal Templar Assassin during Meld, Zeus nonetheless has no way to deal with Refraction.
* Zeus is a rather squishy hero, falling easily to Templar Assassin's high burst damage.
Additional:
* 
Refraction blocks all of Zeus' damage and Zeus has no innate way of removing the instances quickly.
* 
Meld helps burst down Zeus' small health pool while he's still working through the Refraction instances.
* 
Psi Blades allow her to harass and zone Zeus in lane.
* Templar Assassin usually buys Blink Dagger, enabling her to quickly close the gap to Zeus' defensive positioning.
Zeus
* Heroes who can provide True Sight are always credible threats: 
Slardar, 
Bounty Hunter, especially Zeus since his Lightning Bolt provides True Sight without the need to detect her beforehand to apply the debuff. So even a late-coming Zeus can easily scout a large area to reveal her, and she cannot purge herself from his sight with the dispel talent.
Io
* Batrider's 
Flaming Lasso can be used to cancel Io's attempts to escape with Relocate and drag him away from his Tethered target. And since Io doesn't like buying Linken's Sphere, he will be always vulnerable to Batrider's initiations.
* Io's tendency to stick close to it's Tethered target can make Io and it's target vulnerable to Batrider's harrasing.
* Aghanim's Scepter upgraded Flaming Lasso allows Batrider to catch and drag two heroes at once, not just one. Which can potentially turn Io's Tether against him.
Additional:
* Batrider's Flaming Lasso can be used to cancel Io's attempts to escape with Relocate and drag him away from his Tethered target. And since Io doesn't like buying Linken's Sphere, he will be always vulnerable to Batrider's initiations.
* Io's tendency to stick close to it's Tethered target can make Io and it's target vulnerable to Batrider's harrasing.
* Aghanim's Scepter upgraded Flaming Lasso allows Batrider to catch and drag two heroes at once, not just one. Which can potentially turn Io's Tether against him.
Zeus
* Zeus is good against heroes that juke in trees or up cliffs, like Batrider, Monkey King, Spectre, and Tinker, by providing vision in any area with Lightning Bolt, or guaranteeing vision on enemies with Thundergod's Wrath.
Zeus
* Heroes with strong area-of-effect damaging and/or disabling abilities will be able to intercept Underlord and his team when they exit from Fiend's Gate: Luna's Aghanim's Scepter upgraded 
Eclipse, Dawnbreaker's 
Solar Guardian, Axe's 
Berserker's Call, Mars's 
Arena of Blood, Jakiro's Macropyre, 
Dual Breath and Ice Path, Naga Siren's 
Song of the Siren, 
Razor's 
Eye of the Storm and 
Plasma Field, Lina's 
Light Strike Array, Broodmother's 
Spinner's Snare from Aghanim's Scepter, 
Elder Titan's 
Earth Splitter and 
Echo Stomp, Alchemist's 
Unstable Concoction and 
Acid Spray, Queen of Pain's 
Sonic Wave, 
Dark Seer's 
Wall of Replica and 
Vacuum, 
Venomancer's 
Noxious Plague and 
Poison Nova from Aghanim's Scepter, Oracle's 
Fortune's End and 
Rain of Destiny from Aghanim's Shard, Bloodseeker's 
Blood Rite, Enigma's 
Black Hole and 
Midnight Pulse, Shadow Fiend's 
Requiem of Souls, Batrider's Aghanim's Scepter upgraded Flaming Lasso, 
Firefly, 
Flamebreak and 
Sticky Napalm, 
Ancient Apparition's Ice Blast, 
Sand King's 
Epicenter, 
Sand Storm and 
Burrowstrike, Gyrocopter's Call Down, Ember Spirit's Sleight of Fist, Death Prophet's 
Exorcism and 
Silence, Monkey King's 
Wukong's Command, Crystal Maiden's 
Freezing Field, Muerta's 
The Calling, Medusa's 
Stone Gaze, Zeus's Nimbus from Aghanim's Scepter. 
Dark Willow's 
Bramble Maze, Pangolier's 
Swashbuckle, 
Grimstroke's Soulbind, 
Ink Swell and 
Stroke of Fate, 
Earthshaker's 
Echo Slam and 
Fissure, Puck's 
Dream Coil and 
Waning Rift, Winter Wyvern's Winter's Curse, Magnus's 
Reverse Polarity.
Io
* Io can escape from Pit of Malice with Tether or Relocate.
* Relocate can counter Dark Rift's split pushing.
Zeus
* Enchantress has a very low health pool, allowing Zeus to burst her down quickly before she can heal off the damage with Nature's Attendants.
* Zeus will not be affected by Untouchable, as he won't try to attack her with right clicks anyway.
* Zeus can stay out of her attack range while trying to kill her, especially if he has bought an 
Aether Lens.
* Most heroes would want to get on top of Zeus to kill him, but Enchantress does not have this option as doing so would severely limit her damage from Impetus.
* The exception is the laning phase, where Enchantress can gank Zeus if she Enchants a good creep.
Additional:
* Enchantress has a very low health pool, allowing Zeus to burst her down quickly before she can heal off the damage.
* Zeus will not be affected by 
Untouchable, as he won't try to attack her with right clicks anyway.
* Zeus can stay out of her attack range while trying to kill her, especially if he has bought an Aether Lens.
* Most heroes would want to get on top of Zeus to kill him, but Enchantress does not have this option as doing so would severely limit her 
Impetus damage.
* The exception is the laning phase, where Enchantress can gank Zeus if she Enchants a good creep.
Zeus
* Due to Hoodwink's low health and Zeus's high magic damage from Arc Lightning, Lightning Bolt and 
Static Field as well as global abilities from Thundergod's Wrath and Nimbus, he can easily kill her throughout the game and also reveal where Hoodwink is positioned or when she's in trees.
Zeus
* Zeus can easily find Magnus who is often hiding in the trees with Thundergod's Wrath and Lightning Bolt, which allows him to warn allies and disrupt his initiation attempts.
Io
* Heroes with both illusions and summons, for Io has nothing to deal with multiple enemies at once outside from Spirits's weak area-of-effect: Beastmaster, Broodmother, Chaos Knight, Lycan, Naga Siren, Nature's Prophet, Phantom Lancer, Shadow Shaman, Terrorblade, Visage, Warlock, Wraith King.
Zeus
* Heroes who can provide True Sight or semi-reveal enemy heroes as Nature's Prophet is prone to buying 
Shadow Blade: Bounty Hunter, Slardar, Spectre, Zeus, Spirit Breaker.
Io
* Nature's Prophet is extremely easy to gank with Relocate while he's split pushing.
* Tether on a friendly unit can destroy Nature Prophet's trees should he surround himself with 
Sprout as a defense.
Zeus
* Slardar has high priority on building moblity items such as Blink Dagger rather than tank items. Zeus can easily deal large amount of damage to him if not caught out of position first.
Zeus
* Necrophos' 
Ghost Shroud increases the magic damage taken by Necrophos.
* If Zeus builds both an 
Ethereal Blade and Veil of Discord, it almost always guarantees a kill.
Zeus
* Zeus deals enormous amounts of magic damage, being one of the best heroes to burst down Timbersaw early in the game.
* Lightning Bolt's mini-stun can stop Timbersaw's from escaping a fight with Timber Chain.
Additional:
* 
Reactive Armor will not trigger from Zeus's spells or protect Timbersaw from their damage.
* Early game Timbersaw's strength is average and Zeus can heavily aid in bursting him down.
* Late game, if Timbersaw has built a lot of HP items, Zeus's passive Static Field will be more effective at chipping away Timbersaw's large HP pool.
* A Timbersaw who builds 
Pipe of Insight will be much more difficult to kill, as Zeus has no way to hold Timbersaw down, but Timbersaw will have less armor, mana, and damage than normal if he buys this item early game just to counter Zeus.
Zeus
* Arc Lightning allows Zeus to get farm in lane against Shadow Fiend without coming into the range of his Shadowrazes.
* Lightning Bolt can be used to heavily harass Shadow Fiend when he tries to get a last hit.
* Thundergod's Wrath and Lightning Bolt can be used to detect Shadow Fiend if he tries to escape with Shadow Blade.
Io
* Phoenix's limit AoE, damage-over-time abilities give Io plenty of time to save allies with Relocate.
Zeus
* Arc Lightning has a low cooldown can used to pop his Linken's Sphere.
* Lightning Bolt or (Nimbus upgraded from Aghanim's Scepter) detects Weaver during Shukuchi, preventing his ganks.
* Thundergod's Wrath can kill Weaver quickly before he can cast his Time Lapse at low health.
Zeus
* Thundergod's Wrath will often disable Earthshaker's Blink Dagger before a fight starts.
Zeus
* Zeus usually stays at the back in teamfights and it is hard for Sand King to find Zeus and knock him down before Zeus deals his damage.
* All of Zeus' abilities, especially Thundergod's Wrath, disables Sand King's Blink Dagger, effectively reducing Sand King's initiation and counter-initiation potential.
* Lightning Bolt deals damage to Sand King in Sand Storm and reveals him. It also interrupts channeling of Epicenter.
Zeus
* Zeus can break Blink Dagger with his long range abilities and global range ultimate, Thundergod's Wrath.
* Lightning Bolt has a long range and a mini-stun, providing a way for him to cancel Black Hole from safe distances, assuming Enigma doesn't have his Black King Bar.
* Zeus's Aghanim's Scepter grants him Nimbus ability that has a global range and mini-stun, making it an even more effective way to cancel Black Hole before Enigma initiates with Black King Bar.
* Zeus is typically able to position himself at a safe distance from the fight, making him a difficult target to capture in a Black Hole.
Zeus
* Zeus is good against heroes that juke in trees or up cliffs, like Batrider, Monkey King, Spectre, and Tinker, by providing vision in any area with Lightning Bolt, or guaranteeing vision on enemies with Thundergod's Wrath.
Zeus
* Heroes with spells that negate invisibility such as Bounty Hunter, Zeus and Slardar prevent her from saving her allies with Moonlight Shadow.
Zeus
* Heroes with mediocre health pools who rely on armor or evasion to survive fights such as 
Troll Warlord, 
Windranger, and Terrorblade can be killed by Zeus if caught off guard.
Zeus
* Since Windranger is bad against magical damage, heroes with continuous magical damage or magical nukes can blast her: Zeus, Tinker, Leshrac, 
Viper, Skywrath Mage, Lion, Lina, Venomancer.
Io
* 
Duel is very effective against Io due to its low health and armor.
Zeus
* Heroes with global abilities can give Legion Commander's opponent an edge in Duels from anywhere on the map: Nature's Prophet, Ancient Apparition, Zeus, Invoker, Treant Protector
Io
* Tethered heroes are much harder for Legion Commander to kill in Duels.
* Relocate can cancel Duels and save allies.
Io
* Heroes whose abilities can affect multiple enemies at once: Dawnbreaker, Ember Spirit, Lina, Luna, Jakiro, Leshrac, Invoker, Muerta, Dazzle.
Zeus
* Zeus's enormous magical damage output makes Pierce the Veil risky to use without a Black King Bar.
* Zeus does not rely on attack speed, making The Calling nearly pointless against him.
* If Zeus is ever too close to Muerta, he can use 
Heavenly Jump to disengage.
Io
* Heroes that are hard to gank: Axe, Death Prophet, Phantom Lancer, Slark, Centaur Warrunner, Bristleback, Medusa, Mars.
Zeus
* Mars' own father is a formidable foe because Zeus deals massive amounts of magical damage. The high damage, low cooldown nukes of Arc Lightning and Lightning Bolt combined with the percent health magic damage of Static Field will shred Mars' health because it bypasses Bulwark completely.
Io
* Heroes whose abilities can affect multiple enemies at once: Dawnbreaker, Ember Spirit, Lina, Luna, Jakiro, Leshrac, Invoker, Muerta, Dazzle.
Zeus
* Zeus greatly hinders Invoker on the line with his long-range abilities. QW- and QE-Invoker have a very long recharge on abilities, and Zeus' Arc Lightning ability recharges too quickly, which is why he quickly kills a pack of creeps and drives Invoker under his tower, punching and not letting finish off creeps
* Lightning Bolt and Thundergod's Wrath abilities reveal invisibility of enemies, for example Invoker invisibility from 
Ghost Walk ability
Additional:
* Zeus greatly hinders Invoker on the line with his long-range abilities. QW- and QE-Invoker have a very long recharge on abilities, and Zeus' Arc Lightning ability recharges too quickly, which is why he quickly kills a pack of creeps and drives Invoker under his tower, punching and not letting finish off creeps
* Lightning Bolt and Thundergod's Wrath abilities reveal invisibility of enemies, for example Invoker invisibility from Ghost Walk ability
Zeus
* As a spellcaster, silences will nullify him entirely. Some notable examples are Death Prophet, Drow Ranger, Bloodseeker, Disruptor and many others.
* Doom, as usual, fits this description nicely.
Io
* Drow Ranger's lack of escape abilities makes her an easy target for Relocate ganks.
Io
* Heroes that can easily bypass Io's allies to get to Io: Riki, Tusk, Clinkz, Sniper, Slark, Phantom Assassin, Void Spirit, Storm Spirit, Ember Spirit, Earth Spirit, Spirit Breaker, Lifestealer.
Zeus
* Zeus's Lightning Bolt and Thundergod's Wrath provides a short duration of True Sight, revealing Riki while possibly dealing a heavy amount of damage.
* Zeus's Nimbus can be placed directly on top of 
Tricks of the Trade, potentially causing him to be damaged, stunned, and revealed the instant he becomes targetable again.
Io
* Fragile heroes: Bounty Hunter has decent nuking capabilities with Shiruken Toss and Jinada thus making fragile heroes easy picks for ganking. Few examples of such heroes are:Crystal Maiden, Pugna, Skywrath Mage, Io, Witch Doctor, etc.
Zeus
* Lightning Bolt makes roaming behind enemy lines more and more difficult as Zeus becomes powerful enough to spam it. Also, Zeus' Ultimate Thundergod's Wrath reveals Bounty Hunter regardless of his position.
Additional:
* Bounty Hunter has a very low health pool, allowing Zeus to burst him down quickly.
* Zeus can cast Lightning Bolt to gain True Sight in any area he suspects Bounty Hunter may be invisible or any area he thinks Bounty Hunter may have warded.
* If Bounty Hunter tries to escape a gank by using 
Shadow Walk, Zeus can gain vision of him with both Lightning Bolt and Thundergod's Wrath.
Io
* Heroes with either magical, physical or pure damage burst: Bane, Ember Spirit, Leshrac, Lina, Luna, Nyx Assassin, Phantom Assassin, Skywrath Mage, Tinker, Ursa, Void Spirit.
Zeus
* Zeus can easily reveal Tinker's location in the trees with Thundergod's wrath.
* When Zeus has an Aghanim's Scepter, he can use his Nimbus, together with Lightning Bolt to interrupt Tinker's 
Keen Conveyance channelling and cancel Tinker's Blink Dagger.
Additional:
* Due to Tinker's low health pool, Zeus can easily burst Tinker down, while also cancelling 
Rearm.
* Once Zeus gets Aghanim's Scepter, he will gain Nimbus, which allows him to scout out Tinker on the map, especially when he is pushing lanes while hiding in the trees.
Io
* Heroes with both illusions and summons, for Io has nothing to deal with multiple enemies at once outside from Spirits's weak area-of-effect: Beastmaster, Broodmother, Chaos Knight, Lycan, Naga Siren, Nature's Prophet, Phantom Lancer, Shadow Shaman, Terrorblade, Visage, Warlock, Wraith King.
Zeus
* Heroes with global nukes will target and hit Phantom Lancer regardless of his illusions: Zeus
Io
* Terrorblade can easily take advantage of Io's weak durability with 
Reflection and 
Metamorphosis.
* As Io relies on boosting his and his Tethered target's attack speed with Overcharge, Terrorblade can take advantage of this with Reflection, which can damage and slow both, Io and his Tethered target.
* 
Spirits's weak area-of-effect makes it a bad tool to deal with Terrorblade's illusions from 
Conjure Image and 
Manta Style.
* Io's damage output is one of the weakest, therefore Terrorblade will have plenty of time to save himself with 
Sunder.
* However, Terrorblade has no way of stopping Io to escape with Tether or to stop both, Io and his Tethered target to escape with Relocate besides 
Terror Wave from Aghanim's Scepter.
Additional:
* Terrorblade can easily take advantage of Io's weak durability with Reflection and Metamorphosis.
* As Io relies on boosting his and his Tethered target's attack speed with Overcharge, Terrorblade can take advantage of this with Reflection, which can damage and slow both, Io and his Tethered target.
* Spirits's weak area-of-effect makes it a bad tool to deal with Terrorblade's illusions from Conjure Image and Manta Style.
* Io's damage output is one of the weakest, therefore Terrorblade will have plenty of time to save himself with Sunder.
* However, Terrorblade has no way of stopping Io to escape with Tether or to stop both, Io and it's Tethered target to escape with Relocate besides Terror Wave from Aghanim's Scepter.
Zeus
* Arc Lightning and Lightning Bolt can easily burst Terrorblade and his illusions.
* Static Field from Aghanim's Shard can automatically hit everything in a big radius, taking a huge chunk of health out of Terrorblade's illusions, regardless of how much health they have.
Io
* 
Ensnare and Song of the Siren can be used to cancel both, Tether and Relocate and to close the distance on Io.
* 
Rip Tide combined with illusions from 
Mirror Image often finish off Io before he can save himself with Tether or Relocate.
* Spirits's weak area-of-effect makes it a bad tool to deal with Naga Siren's illusions from Mirror Image.
* Once Naga Siren buys Aghanim's Scepter, she can gain access to 
Reel In, which not only allows her to cancel both, Tether and Relocate, but also to pull Io to herself and her team while he is affected with Ensnare, similarly to Batrider's Flaming Lasso.
* Aghanim's Shard upgraded Song of the Siren can also heal the hero Io and his Tethered targed try to gank.
Additional:
* Ensnare and Song of the Siren can be used to cancel both, Tether and Relocate and to close the distance on Io.
* Rip Tide combined with illusions from Mirror Image often finish off Io before he can save himself.
* Spirit's weak area-of-effect makes it a bad tool to deal with Naga Siren's illusions from Mirror Image.
* Once Naga Siren buys Aghanim's Scepter, she can gain access to Reel In, which not only allows her to cancel both, Tether and Relocate, but also to pull Io to herself and her team while he is affected with Ensnare, similarly to Batrider's Flaming Lasso.
* Aghanim's Shard upgraded Song of the Siren can also heal the hero Io and his tethered targed try to gank.
Zeus
* Zeus's abilities deal high amounts of burst magical damage, which ignores Naga Siren's high armor.
* Arc Lightning is a good way to destroy Naga Siren's illusions due to it's capabilities to bounce between enemies.
* Static Field from Aghanim's Shard can automatically hit everything in a big radius, taking a huge chunk of health out of Naga Siren's illusions, regardless of how much health they have.
Io
* 
Lucent Beam can be used to cancel both, Tether and Relocate.
* Like with Leshrac's Diabolic Edict, Lightning Storm and Pulse Nova abilities. Luna's 
Moon Glaives and Eclipse abilities can make short work of Io and its tethered ally, particularly when upgraded with Aghanim's Scepter.
Additional:
* Lucent Beam and 0.25s Eclipse Lucent Ministun talent for Eclipse can be used to cancel both, Tether and Relocate.
* Luna's Moon Glaives and Eclipse abilities can make short work of Io and its tethered ally, particularly when upgraded with Aghanim's Scepter.
Zeus
* Zeus's highly damaging nuke spells with low cooldowns is not something Luna can go against, though Luna can win against Zeus in late game.
* Thundergod's Wrath can be used before a fight to harm Luna before she activates Black King Bar, reducing her survivability for that fight.
* For the same reasons, Zeus makes a very powerful ally for Luna when they are in the same team.
Zeus
* Zeus likes to stay far back in fights, dealing his damage uninterrupted, but once he gets hooked into the fight, he usually dies very quickly.
* Pudge's high strength from Flesh Heap makes it very hard for Zeus to burst him down.
* Zeus' low health pool makes him very vulnerable to the damage from Meat Hook, Rot and Dismember.
Additional:
* 
Meat Hook's high range allows Pudge's team to drag Zeus in the middle of the fight and abuse his frailty.
* 
Flesh Heap's health and magic resistance bonus makes Pudge exceptionally resistant to Zeus' nukes. In later stages of the game, Zeus is usually unable to seriously damage Pudge at all. Even Static Field, which deals damage based on a percentage of the enemy's health, won't be doing much.
* Even if Zeus buys a Black King Bar, Meat Hook and 
Dismember still disable him for a long time, usually causing Zeus' quick death.
* Zeus is vulnerable to early ganks, which Pudge excels at.
Io
* Tether and Overcharge makes it much harder for Pudge to kill a target with Meat Hook, and Relocate can save the Io's ally while Dismember is being channeled.
Zeus
* Thundergod's Wrath strikes only the first Meepo.
* Zeus has low mobilty so consecutive 
Earthbinds are easy to hit and he'll quickly die from 
Poofs.
Io
* Tether helps Io escape from Earthbind even if Meepo has Blink Dagger.
* Io's Spirits can pressure Meepo while laning and will usually hit at least one of his clones.
Io
* 
Strafe, 
Tar Bomb and 
Burning Barrage from Aghanim's Shard allow Clinkz to quickly kill Io due to its low armor.
* Clinkz iz a hero that very often goes for Orchid Malevolence, and its upgrade Bloodthorn. Alternatively, Clinkz also loves to buy 
Gleipnir. And if Clinkz has both of them, he will be able to root and silence Io and prevent him from escaping with either Tether or Relocate.
Zeus
* Zeus can reveal Clinkz with Lightning Bolt.
* He is vulnerable to Zeus's magical nukes, due to his low health pool.
Io
* Lich's 
Chain Frost forces Io to either give up providing buff to his ally with Tether or suffer devastating damage with his Tethered ally.
* Lich can easily use 
Sinister Gaze to disable Io from getting away with Tether or Relocate.
Zeus
* Lich does not pose a big threat to Zeus in teamfights, as his spells don't have great cast range and Zeus should be too far back for a Chain Frost to bounce among him and his allies.
* Lich has a low health pool, allowing Zeus to burst him down quickly.
Zeus
*
Enrage will make it very difficult to burst him down.
* Zeus has little armor, HP and mobility; Ursa's favorite kind of target.
Io
* Heroes with either magical, physical or pure damage burst:
Bane, 
Ember Spirit, 
Leshrac, 
Lina, 
Luna, 
Nyx Assassin, 
Phantom Assassin, 
Skywrath Mage, 
Tinker, 
Ursa, 
Void Spirit.