Sand King
* 
Boulder Smash will push Sand King out of Sand Storm to reveal his position or an activated Epicenter off of Earth Spirit's allies, potentially wasting his combo
* 
Rolling Boulder and 
Geomagnetic Grip allow Earth Spirit to easily stun and silence Sand King and interrupt the channeling of Epicenter, completely ruining his initiation.
Io
* Squishy heroes (
Io, 
Crystal Maiden, 
Lina...), as Earth Spirit can deal tons of damage with Magnetize.
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.
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.
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.
Sand King
* Both 
Arcane Curse and 
Last Word punishes casters with spammable spells such as Sand King.
* As a strength caster, 
Intelligence Steal reduces Sand King's mana pool even more.
* 
Global Silence silences Sand King, effectively reducing Sand King's initiation and counter-initiation potential. It can also interrupt channeling of Epicenter.
Sand King
* 
Ravage, being an AoE disable, cancels Epicenter's channeling from a long range, limiting his potential to counter-initiate.
* This can be remedied, however, by first using a 
Black King Bar, then channel Epicenter, then finally initiate with 
Blink Dagger.
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
* 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.
Sand King
* 
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.
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
* 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
* 
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.
Sand King
* Ghostship helps your team soak up damage from 
Epicenter, especially if he initiates during the battle.
* 
Sand King can't dodge X Marks the Spot - Torrent combo by his abilities. Torrent drags him out of his 
Sand Storm
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.
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.
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.
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.
Sand King
* Burrowstrike is one of the best and easiest steals for Rubick and Sand King should be careful when playing against him - it's much better to give away Sand Storm.
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.
Sand King
* 
Lifestealer's Rage negates Sand King's spells which do magical damage.
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.
Sand King
* Heroes that rely on slows to get kills: Lifestealer, 
Night Stalker, 
Ursa, Phantom Assassin, 
Terrorblade.
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.
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 whose abilities can affect multiple enemies at once: 
Dawnbreaker, Ember Spirit, Lina, 
Luna, 
Jakiro, 
Leshrac, 
Invoker, 
Muerta, 
Dazzle.
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 that are hard to gank: 
Axe, 
Death Prophet, Phantom Lancer, Slark, 
Centaur Warrunner, 
Bristleback, 
Medusa, 
Mars.
Io
* Heroes that are hard to gank: Axe, Death Prophet, Phantom Lancer, Slark, Centaur Warrunner, Bristleback, Medusa, Mars.
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.
Io
* Heroes that are hard to gank: Axe, Death Prophet, Phantom Lancer, Slark, Centaur Warrunner, Bristleback, Medusa, Mars.
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.
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
* 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.
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
* 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 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 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 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.
Io
* Heroes that are hard to gank: Axe, Death Prophet, Phantom Lancer, Slark, Centaur Warrunner, Bristleback, Medusa, Mars.
Io
* Heroes whose abilities can affect multiple enemies at once: Dawnbreaker, Ember Spirit, Lina, Luna, Jakiro, Leshrac, Invoker, Muerta, Dazzle.
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
* 
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.
Sand King
* Sand King is a strong ganker, allowing him to shut down squishy heroes in the early game: Phantom Assassin, Clinkz, Sniper, 
Enchantress.
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.
Sand King
* Heroes with no mobility will take some good damage from Sand King's spells: 
Dragon Knight, Jakiro, Pugna, 
Earthshaker.
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.
Sand King
* Heroes that rely on slows to get kills: Lifestealer, Night Stalker, Ursa, Phantom Assassin, Terrorblade.
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.
Sand King
* Since Naga Siren is a hero who barely goes for Black King Bar, she is vulnerable to nukers with strong magical damage and big area-of-effect spells in every game more than any other carry heroes: Sand King, Jakiro, Leshrac, Lina, Earthshaker, Zeus.
Sand King
* Heroes with blink or movement abilities, which are disabled by Pounce's leash: 
Anti-Mage, Earth Spirit, 
Faceless Void, 
Magnus, 
Mirana, 
Monkey King, 
Morphling, 
Pangolier, Phantom Assassin, 
Phoenix, 
Puck, 
Queen of Pain, Riki, Sand King, Spirit Breaker, 
Timbersaw, Tusk.
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.
Sand King
* Slark will have a hard time killing Sand King because of the survivability he gets from Burrowstrike and Sand Storm.
* 
Shadow Dance, which usually allows Slark to survive fights, is ineffective against Sand King's AoE damage.
Sand King
* 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.
Sand King
* Heroes with powerful area-of-effect disables can initiate on Meepo and his clones and shut him down, such as Enigma, Invoker, Magnus, Puck, and Sand King.
Additional:
* Burrowstrike can stun multiple Meepos, making them vulnerable targets.
* Epicenter and Sand Storm's AoE damage ensures all Meepo clones get damaged, making it hard for Meepo to choose which one to flee as all are taking damage at the same rate.
* Just be aware when using Sand Storm to escape, as Meepo has good AoE damage and disables, which, as explained in the "Bad Against" section, works well against an invisible Sand King.
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
* 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.
Sand King
* Sand King's 
Caustic Finale combined with Sand Storm will kill Treants easily.
* Sand King can interrupt Teleportation with Burrowstrike, even through Sprout.
Additional:
* With Caustic Finale, Sand King can easily kill the treants from 
Nature's Call.
* Burrowstrike allows Sand King to prevent Nature's Prophet from using 
Teleportation inside of his 
Sprout.
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.
Sand King
* Sand King can quickly remove her 
Refraction with his Sand Storm.
* Once Refraction is down, she is very vulnerable to Epicenter's high magic damage.
Sand King
* Burrowstrike, Sand Storm, Caustic Finale and Epicenter will deal a large amount of damage to Chen and his creeps.
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.
Io
* Drow Ranger's lack of escape abilities makes her an easy target for Relocate ganks.
Sand King
* Sand King is a strong ganker, allowing him to shut down squishy heroes in the early game: Phantom Assassin, Clinkz, Sniper, Enchantress.
Sand King
* Heroes with no mobility will take some good damage from Sand King's spells: Dragon Knight, Jakiro, Pugna, Earthshaker.
Sand King
* Any hero who can counter-initiate in anticipation without getting caught in Reverse Polarity: 
Sven, Omniknight, Enigma, Luna, Naga Siren, Mars, Jakiro, Venomancer, Elder Titan, Faceless Void, 
Rubick, 
Keeper of the Light, Pugna, Invoker, 
Spectre, Alchemist, 
Treant Protector, Lina, Oracle, Zeus, Shadow Shaman, Phoenix, Razor, 
Huskar, Batrider, 
Kunkka, 
Tidehunter, Wraith King, Sand King, Medusa, Dawnbreaker.
Sand King
* Heroes with no mobility will take some good damage from Sand King's spells: Dragon Knight, Jakiro, Pugna, Earthshaker.
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.
Sand King
* Heroes that rely on slows to get kills: Lifestealer, Night Stalker, Ursa, Phantom Assassin, Terrorblade.
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.
Sand King
* All of Sand King's abilities deal AoE damage.
* However, Epicenter is usually a non-issue against Doppelganger.
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.
Sand King
* Sand King's massive area damage output, particularly Epicenter, allows him to quickly take down Chaos Knight and his illusions.
* Sand King can also apply Caustic Finale to illusions with attacks for extra damage when they die.
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.
Sand King
* Burrowstrike can be used as an escape or initiation against Broodmother.
* Sand Storm quickly kills any spiderlings caught inside if Sand King can manage to stun them.
Additional:
* Caustic Finale allows Sand King to easily kill Broodmother's Spiderlings throughout the game.
* Sand King can usually catch a split pushing Broodmother with Blink Dagger and Burrowstrike.
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.
Sand King
* Sand King's Sand Storm damages familiars quickly whittling them down in health, rendering them vulnerable.
* Sand King's Epicenter quickly damages and destroys familiars.
Io
* 
Take Aim and 
Assassinate allow Sniper to reach Io even if it stays in the backline.
Sand King
* Sand King is a strong ganker, allowing him to shut down squishy heroes in the early game: Phantom Assassin, Clinkz, Sniper, Enchantress.
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
* 
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.
Sand King
* Burrowstrike allows Sand King to escape from Eclipse or to close the gap on Luna and finish her off.
* Sand Storm allows Sand King to harass Luna more efficiently than she does with Lucent Beam, as it makes him invisible for it's duration and while in it, rendering him safe from both, Lucent Beam and Eclipse and forcing Luna to buy 
Dust of Appearance more often.
* Caustic Finale allows Sand King to deal serious damage to both, Luna and her allies, which is especially hazardous in laning stage as Luna's attack range is short.
* Epicenter combined with Burrowstrike and Sand Storm can often kill Luna before she can do anything because of her low health and strength gain.
* Overall, Sand King forces Luna to play more defensively instead of offensively, and for the same reasons, Sand King makes a very powerful ally for Luna when they are in the same team.
Additional:
* Burrowstrike allows Sand King to escape from Eclipse or to close the gap on Luna and finish her off.
* Sand Storm allows Sand King to harass Luna more efficiently than she does with Lucent Beam, as it makes him invisible for it's duration and while in it, rendering him safe from both, Lucent Beam and Eclipse and forcing Luna to buy Dust of Appearance more often.
* Caustic Finale allows Sand King to deal serious damage to both, Luna and her allies, which is especially hazardous for Luna during the laning stage as Luna's attack range is short.
* Epicenter combined with Burrowstrike and Sand Storm can often kill Luna before she can do anything because of her low health and strength gain.
* Overall, Sand King forces Luna to play more defensively instead of offensively, and for the same reasons, Sand King makes a very powerful ally for Luna when they are in the same team.
Sand King
* Pugna's 
Nether Ward damages Sand King when he channels Epicenter, preventing him from using Blink Dagger afterward.
Sand King
* Heroes with no mobility will take some good damage from Sand King's spells: Dragon Knight, Jakiro, Pugna, Earthshaker.
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.
Sand King
* Phantom Assassin relies on her 
Blur to stay alive, but is very vulnerable to Sand King's heavy magic damage.
* With Burrowstrike, Sand King can often catch Phantom Assassin before she can use her Black King Bar.
* Sand King can dodge 
Stifling Dagger with Sandstorm.
* Phantom Assassin has a hard time killing Sand King because of his high mobility.
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.
Sand King
* Heroes that rely on slows to get kills: Lifestealer, Night Stalker, Ursa, Phantom Assassin, Terrorblade.
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.
Sand King
* Heroes who rely on damage over time as Spiked Carapace can block and reflect only one instance of damage: Jakiro, 
Viper, Venomancer, Huskar, Ember Spirit, Dark Seer, Sand King, 
Doom, Dawnbreaker. However, this also means they are easily stunned.
Sand King
* Sand King has nothing to deal with 
Supernova, as none of his spells are effective.
* The damage-over-time abilities of Phoenix disable Sand King's Blink Dagger very often.
Io
* Phoenix's limit AoE, damage-over-time abilities give Io plenty of time to save allies with Relocate.
Io
* 
Duel is very effective against Io due to its low health and armor.
Io
* Tethered heroes are much harder for Legion Commander to kill in Duels.
* Relocate can cancel Duels and save allies.
Sand King
* Quill Spray will hit Sand King inside
Sand Storm, damaging him and putting Sand King's 
Blink Dagger on cooldown, preventing him from escaping.
Epicenter's numerous damage ticks will trigger Bristleback's passive repeatedly during teamfights.
*
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.