* Attacks from Boars and the attack speed boost from Inner Beast will quickly wear down Refraction.

* Ion Shell destroys Refraction's protection stacks in short time.
* Surge ignores the massive slow from Psionic Trap.

* Because only one clone needs to be killed in order to kill Meepo, heroes that excel at singling out enemies can also be a detriment to him, such as Batrider, Beastmaster, Pudge and Clockwerk.

* Dark Seer can take great advantage of Divided We Stand by putting an Ion Shell on a clone in order to harass them effectively.
* Vacuum can take a single Meepo and disable them for him and his teammates to take out.

* Illusion or summon-based heroes can be a problem to Viper due to his lack of AoE damage: Naga Siren, Phantom Lancer, Beastmaster

* Heroes who do not have nor rely on passive abilities make Nethertoxin much less effective: Clinkz, Pugna, Nature's Prophet, Dark Seer, Lycan, Tusk

* Dark Seer's Vacuum and Ion Shell allows him to clear the wave of Terrorblade's illusions.
* Wall of Replica and Normal Punch from Aghanim's Shard can create stronger illusions of Terrorblade.
* If Dark Seer can use Vacuum to help teammates land their AoE skills, Terrorblade will be quickly killed before he even gets a chance to use Sunder.
Additional:
* Dark Seer's Vacuum and Ion Shell allows him to clear a wave of Terrorblade's illusions.
* Because Terrorblade often builds items that require Ultimate Orb like Manta Style and Eye of Skadi, Dark Seer can create a very strong illusion of Terrorblade with Wall of Replica and Normal Punch from Aghanim's Scepter.
* If Dark Seer can use Vacuum to help teammates land their AoE abilities, Terrorblade will be quickly killed before he even gets a chance to use Sunder.

* Wild Axes destroys large amounts of trees specially upgraded with Aghanim's Scepter,

* Primal Roar and the slow from Boars make kiting Tiny very easy.

* Wraith King's lack of area of effect spells makes him easily overwhelmed by Beastmaster's summons.

* Primal Roar and the slow from Boars make kiting Troll Warlord very easy.

* Inner Beast helps Beastmaster's team destroy Supernova quickly.

* Venomancer is a low health hero and low range hero who is easy to harass with Ion Shell on a creep in the early game.
* Venomancer depends entirely on all his slows to keep distance or chase, but since Surge ignores slows, it is nearly impossible for Venomancer to hunt or run away from Dark Seer or his surged teammates.

* Surge allows for Dark Seer and his allies to escape from Upheaval due to it ignoring any slow.

* Primal Roar and the slow from Boars makes kiting Ursa very easy.

* Living Armor can be destroyed quickly with Ion Shell.

* Ion Shell zones out Broodmother in the laning phase, and can kill her spiderlings if used on one Spiderling in a group.
* Vacuum can pull Broodmother out of the treeline.
Additional:
* Ion Shell is a very powerful weapon against Broodmother's Spiderlings and makes her laning much harder.

* Beastmaster's Hawk can find Tinker easily while he is pushing or blinking into trees.

* Primal Roar allows Beastmaster to keep Lycan in place after he used his Shapeshift.

* Heroes with disables that ignore spell immunity will render Phantom Assassin quite useless in teamfights throughout the game: Axe, Enigma, Vengeful Spirit, Doom, Bane, Beastmaster, Pudge, Medusa.

* Heroes with other kind of disables that pierce spell immunity can hold Pangolier in place during Rolling Thunder: Axe, Beastmaster, Enigma, Magnus, Pudge, Batrider, Bane, Winter Wyvern

* Certain heroes can mess up with Pangolier's positioning and timing (especially if he intends to use Rolling Thunder during combat): Vengeful Spirit, Keeper of the Light, Huskar, Dark Seer

* Heroes with escape abilities : Anti-Mage Dark Seer Slark Storm Spirit Windranger Weaver can kite Lifestealer due to him having no lockdown

* Heroes who relies on illusions and summons (Beastmaster, Chaos Knight, etc.).

* Long ranged disables, especially those that pierce spell immunity, cancel Black Hole: Beastmaster's Primal Roar, Bane's Fiend's Grip, Faceless Void's Chronosphere, Magnus's Reverse Polarity, Axe's Berserker's Call, Pudge'sMeat Hook.

* Skywrath Mage also has a terrible time fighting against anything that isn't a hero. His skills are mostly target-based and he has terrible strength and agility, he can easily be kited or harassed by illusion-based heroes like Chaos Knight and Phantom Lancer, or by Heroes that summon other units like Lone Druid, Lycan and Beastmaster.

* Heroes who rely on damage over time as Spiked Carapace can block and reflect only one instance of damage: Venomancer, Huskar, Ember Spirit, Dark Seer, Sand King, Doom, Dawnbreaker.

* Heroes that rely on illusions will suffer against Ion Shell, which kills them very quickly: Phantom Lancer, Chaos Knight, Naga Siren, Meepo.

* The haste provided by Dark Seer's Surge or a {Rune:Haste} renders your slows ineffective.

* Heroes that rely on illusions will suffer against Ion Shell, which kills them very quickly: Phantom Lancer, Chaos Knight, Naga Siren, Meepo.

* Dark Seer can pull together Spectre's illusions with Vacuum, and Wall of Replica creates an illusion of Spectre that deals massive damage.

* Heroes with illusions and summons can manfight Night Stalker: Terrorblade, Beastmaster, Broodmother.

* Dark Seer can increase the movement speed of allies with Surge, breaking Static Link.

* Heroes with summons or illusions can counter Flux, such as Beastmaster , Chen, or Shadow Demon.

* The Hawk can easily find Monkey King while he is sitting on a tree.
* Wild Axes can knock out Monkey King from tree.
* Boars drastically reduce Monkey King's attack speed, making it harder for him to gain Jingu Mastery stacks.
Additional:
* Wild Axes can chop down trees, making it difficult for Monkey King to utilize Tree Dance well.
* Call of the Wild Hawk can scout Monkey King when he is perched on top of trees.
* Primal Roar can stun Monkey King for a lengthy duration even with spell immunity.

* Primal Roar takes Sven out of the fight completely, even with Black King Bar.

* Heroes who rely on high mobility are especially vulnerable to Primal Roar: Storm Spirit, Ember Spirit, Queen of Pain.

* Heroes that rely on illusions will suffer against Ion Shell, which kills them very quickly: Phantom Lancer, Chaos Knight, Naga Siren, Meepo.

* Heroes with disables that go through spell immunity can end Bloodseeker before he has the chance to do anything: Batrider, Beastmaster

* Heroes who rely on high mobility are especially vulnerable to Primal Roar: Storm Spirit, Ember Spirit, Queen of Pain.

* Dark Seer's Vacuum and Ion Shell can clear a wave of Chen's Creeps effectively.
* Surge applies haste movement and negates the slow from Hand of God, allowing Dark Seer to easily escape from Chen and his creeps.