* Phantom Lancer can effortlessly overwhelm Morphling with a large number of illusions. It becomes even more effective with {Item ID:Diffusal Blade}, which takes away his mana in the process.
* Doppelganger can be used to dodge Adaptive Strike combo and create confusion with two additional illusions.
* Eye of Skadi can be bought to slow and negate the health regeneration from Attribute Shift, and a common item for Phantom Lancer.

* Phantom Lancer's Doppelganger has a low cooldown and applies a basic dispel on PL, making it hard to keep Corrosive Haze on him.
* Phantom Lancer usually purchases Manta Style which provides another basic dispel to remove Corrosive Haze with.
* Besides Slithereen Crush, Slardar does not have another way to deal with illusions and has a low mana pool, which allows Phantom Lancer with Diffusal Blade to quickly build up illusions while draining Slardar's mana.
* Phantom Rush outruns Guardian Sprint, forcing Slardar to Blink away or use Slithereen Crush defensively to avoid being killed.

* Earthbind disables Waveform, effectively keeping Morphling in place for an extended period of time, allowing Meepo to deal considerable damage with Poof.

* Slardar does not do well against multiple targets, as his only way to damage multiple targets is Slithereen Crush.
* Meepo's Earthbind will root Slardar, making him unable to chase/escape for the time being. Also, Poof's low cooldown and high damage can burst Slardar down rather quickly.

* Abaddon can cast Aphotic Shield on any of his allies to immediately dispel Corrosive Haze and/or the stun and the slow components of Slithereen Crush.
* All of Slardar's debuffs are also removed if Abaddon's Borrowed Time triggers.

* Morphling's high armor is primarily from morphing agility, which is reduced by Natural Order therefore making the hero very vulnerable when it has morphed a lot into agility.
* Morphling usually will Morph into high agility and low strength. This can be taken advantage of with a good stun or silence or by bursting him down before he has the time to Morph back to strength.
* Morphling is very vulnerable to Blade Mail under Natural Order and can easily burst himself down with his own auto-attacks or his magical damage combo.
Additional:
* Most of Morphling's armor comes from his high agility and it is reduced by Natural Order.
* However, the aura has only 350 range and Elder Titan can be bursted down by Morphling's nuke combo if he isn't careful.

* Fortune's End applies a basic dispel which can be used to dispel Corrosive Haze, or even Slardar's own Guardian Sprint.
* False Promise is able to dispel Corrosive Haze and Slithereen Crush stun/slow from any allies Oracle chooses to cast it on.
* Fate's Edict can also be cast on Slardar to prevent him from proccing his Bash of the Deep.

* Jumping on Axe with Waveform will make Morphling an easy target for a counter-initiation with Berserker's Call.
* Morphling is often played at low health to maximize the bonuses from Attribute Shift (Agility Gain), and also because his abilities cost health to use. This makes him especially vulnerable to Culling Blade.
* However, Morphling is a common Linken's Sphere carrier to block Culling Blade, which may force Axe to use Battle Hunger to pop the Spell Block first.
* Attribute Shift (Agility Gain) gives Morphling no protection against the pure damage of Culling Blade. Its attack speed bonus also means that Counter Helix will proc more often.

* Arcane Orb deals pure damage, effectively bypassing Morphling's high armor from Attribute Shift (Agility Gain).
* Sanity's Eclipse is more effective against a low health and mana pool Morphling, enabling Outworld Destroyer to burst Morphling down before he can shift to Strength.
Additional:
* Arcane Orb deals high damage regardless of Morphling's high armor from Attribute Shift (Agility Gain).
* Because of Morphling's very low intelligence gain and base intelligence, Sanity's Eclipse will almost always be effective against Morphling.

* Fire Spirits greatly reduces Slardar's already low starting attack speed (which Bash of the Deep relies on), making the laning phase very hard for him and discouraging Slardar from aggressively threatening lane kills.
* Supernova, ignoring Phoenix's lack of armor and Slardar's high damage single hits, is extremely hard for Slardar to take down on his own, especially after being hit by Fire Spirits.
* Icarus Dive is one of the longest distance escape spells in the game, and can help a good Phoenix escape from Slardar before he gets a Blink Dagger. However, the high cooldown means Phoenix is vulnerable to backstabs from any roamers after said spell is used.
* Slardar can interrupt an Icarus Dive from completing the flight with both of his stuns, however, likely leading to death if Supernova is on cooldown.
* A lot of the items a Phoenix builds throughout the game naturally counter Slardar. Shiva's Guard, Heaven's Halberd and Eul's Scepter of Divinity all stall Slardar's normal attacks in some way, while Spirit Vessel's percentage-based damage is good against his innate durability.

* Geomagnetic Grip is not blocked by Linken's Sphere and can silence Morphling, preventing Morphling from using Waveform or Attribute Shift to escape from ganks.
* In addition, Boulder Smash and Rolling Boulder provide a solid lockdown if used together.

* Ice Blast stops Morphling from gaining additional health with Attribute Shift.
* Using Attribute Shift would even bring Morphling closer to the shatter threshold.
* In the lane, Ice Vortex slows Morphling's already poor movement speed to a crawl; this, coupled with the amplification of magic damage, can set up an early kill on Morphling if Ancient Apparition has a suitable lane partner.
Additional:
* Ice Blast stops Attribute Shift (Strength Gain) from recovering adional health, and using it will even bring Morphling closer to the shatter threshold.
* In lane, Ice Vortex slows Morphling's already poor movement speed to a crawl; this, coupled with the amplification of magic damage, can set up an early kill on Morphling if Ancient Apparition has a suitable lane partner.

* 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.

* Light Strike Array catches Morphling while he jumps in from Waveform and also prevents Morphling from using his abilities.
* Laguna Blade can kill Morphling quickly before he shifts into Attribute Shift (Strength Gain).

* Mana Drain rapidly saps Morphling's already low mana pool, making him unable to use Waveform or Adaptive Strike. Additionally, Hex prevents these abilities as well.
* An Earth Spike and Finger of Death combo can burst an unwary Morphling down if he has his strength fully shifted to agility.

* Arcane Bolt's low cooldown allows him to deal consistent damage to Morphling, and is a viable way to disable Linken's Sphere.
* Ancient Seal prevents Morphling from using any of his skills, giving Skywrath Mage and his team ample time to burst Morphling down.
* Mystic Flare coupled with a stun/root can easily burst Morphling down, especially if he has more stats shifted to Agility.
* Alternatively, Morphling can use Morph to use Skywrath Mage's own silence and nukes against him.

* Rubick's ability to steal Attribute Shift (Strength Gain) makes him extremely annoying to deal with because Rubick's shifted attributes will remain even if he steals a new spell.
* If Rubick moves enough points to strength and then steals Adaptive Strike, he will have a powerful 3-second ranged stun in his arsenal as well.
* Waveform provides a reliable nuke/escape to Rubick.
* Rubick can steal most abilities Morphling uses while Morphed, allowing Rubick to steal his own allies' abilities if the Morphling is not careful.
Additional:
* Morphling's abilities can grant unrivaled utility for Rubick.
* Attribute Shift (Strength Gain) is a great spell that has a longlasting effect, since the attribute change is permanent even after losing the ability. By casting the spell, Rubick becomes significantly tanky after pumping all his agility into strength.
* As the cost of the shift, Rubick's attack speed as well as his armor is hindered. Since the right click damage of Rubick is relatively trival in teamfights, armor items such as Medallion of Courage or Buckler could greatly increase Rubick's effective health to physical damage.
* Rubick must be careful not to confuse Attribute Shift (Strength Gain) with Attribute Shift (Agility Gain).
* Adaptive Strike (Strength) is a long-ranged stun.
* If Attribute Shift (Strength Gain) has been stolen and cast, the spell can stun the enemy for 3 seconds. The stun counters mobile heroes such as Morphling.
* Waveform is a damaging pseudo-blink, giving Rubick much needed mobility and farming potential.

* Sharpshooter can kill easy when Morphling is going on full agility strategy (Only in early and mid game).
* Scurry can help to catch up Morphling when using Waveform or for escape.

* Time Dilation affects Morphling's low cooldown spells, making them unusable for a long time, rendering Morphling nearly useless.
* Morphling cannot use Attribute Shift while he is inside Chronosphere which makes it easy to kill him.

* Morphling usually has low max health due to shifting strength into agility, which combined with Blast Off's silence will prevent him from using Waveform and Adaptive Strike (Strength), leaving him defenseless and making him an easy target to burst down.

* Winter Wyvern's Winter's Curse turns Morphling's high attack damage and attack speed against his targeted teammate.

* Illusion heroes like the aforementioned Phantom Lancer or Naga Siren, or heroes that tend to buy Manta Style, like Luna or Juggernaut, will give Slardar a hard time, as his damage is single-targeted.

* Heroes with silencing abilities that are not blocked by Linken's Sphere, like Puck's Waning Rift, Death Prophet's Silence or Silencer's Global Silence.

* Tidehunter's Kraken Shell dispels Corrosive Haze and Bash of the Deep's stun if enough damage is taken. Anchor Smash and Kraken Shell's damage block also reduces Slardar's damage.

* Enigma can be a perfect counter-initiator with his ultimate. A perfectly timed Black Hole will turn the tide of any initiation, especially from heroes like; Spirit Breaker, Legion Commander, Axe, Puck, and Slardar.

* Underlord's Atrophy Aura reduces Morphling's high base damage gained through agility shift.

* Necrophos's Reaper's Scythe can finish off a low-health Morphling.

* Heroes with silencing abilities that are not blocked by Linken's Sphere, like Puck's Waning Rift, Death Prophet's Silence or Silencer's Global Silence.

* Illusion heroes like the aforementioned Phantom Lancer or Naga Siren, or heroes that tend to buy Manta Style, like Luna or Juggernaut, will give Slardar a hard time, as his damage is single-targeted.

* Heroes that rely on right-clicks will find that their attacks will miss a lot, due to Whirling Axes (Melee)'s miss chance. Such heroes include Phantom Assassin, Terrorblade, and Morphling.

* Jakiro's early pushing ability from Liquid Fire makes Jakiro very strong against heroes, that take a long time to get online: Morphling, Naga Siren, Spectre.

* Heroes with high base damage (Morphling, Tiny, Drow Ranger), heroes with mana burning abilities (Anti-Mage), and Diffusal Blade users (Juggernaut or Riki) will suffer from Reflection's illusions.

* Terrorblade starts out with and gains a lot of armor from his agility growth. His illusions also make it difficult for Slardar to focus down the real Terrorblade.

* Arc Warden can counter Morphling's strong pushing capabilities by using Magnetic Field to protect buildings.
* Arc Warden also often builds an Orchid Malevolence or Bloodthorn, which can prove dangerous for Morphling.
* Arc Warden can easily break Linken's Sphere with Flux and then slow him with Spark Wraith, making Arc Warden's Tempest Double a legitimate threat as well.

* While Morphling can burst her down with Adaptive Strike (Agility), Death Prophet does have tools to disrupt him. A Morphling affected by Silence makes it unable to use Attribute Shift (Strength Gain) to increase its health pool or use Waveform to escape.

* Sacred Arrow's long stun duration can prevent Morphling from casting his Waveform or Morph Replicate, making him unable to escape and easier to gank.
* Moonlight Shadow also allows Mirana's team to surprise Morphling while he tries to push towers.
* Mirana usually buys Linken's Sphere to protect herself from single-target abilities, making Morphling's Adaptive Strike and Ethereal Blade harder to use on her.
* However, Mirana also provides a chance to become a good Morph target, allowing Morph to use Leap to run away, if necessary.

* Illusion heroes like the aforementioned Phantom Lancer or Naga Siren, or heroes that tend to buy Manta Style, like Luna or Juggernaut, will give Slardar a hard time, as his damage is single-targeted.

* Bloodseeker's Rupture forces Slardar to stay still during fights, preventing Slardar from using Guardian sprint to move in and out of fights. This takes away the ability to initiate and re-initiate with Slithereen Crush's low cooldown. Due to the increased move speed from Guardian Sprint, Slardar can lose health at about 160% the rate of normal heroes while under Rupture. Bloodseeker's Thirst also gives him enough move speed so that he's one of the few heroes who can outrun or catch up to a Slardar during Guardian Sprint.

* Heroes who just want to farm and avoid Lone Druid early will find it very hard to do so when he starts knocking on towers: Templar Assassin, Phantom Assassin, Ember Spirit, Morphling.

* 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.

* Counterspell's bonus magic resistance causes the Waveform and Adaptive Strike combo to deal significantly less damage.
* Counterspell's active component can reflect the Adaptive Strike back into Morphling, dealing significant damage or even killing him.
* Mana Break combined with Manta Style can quickly burn away Morphling's mana, leaving him unable to use his spells. Black King Bar can no longer be reliably used against Anti mage due to its 50 mana cost.

* Attribute Shift (Strength Gain) may not be quick enough to fend off an attacking Drow Ranger.
* Morphling likes to sit on low health with high agility, something Drow Ranger does not particularly care for and will still hit him hard with Marksmanship procs.
* Morph is a similar story, none of Drow Ranger's spells are particularly good against her.

* Low-health, normally mobile carries who rely entirely on raw attack damage are vulnerable to Bane's nukes and disables: Anti-Mage, Clinkz, Drow Ranger, Faceless Void, Gyrocopter, Juggernaut, Meepo, Mirana, Monkey King, Morphling, Phantom Assassin, Phantom Lancer, Riki, Shadow Fiend, Slark, Sniper, Terrorblade, Troll Warlord, Weaver.

* Void Spirit can greatly pressure Morphling's farm, which is very bad for a hero who needs a large amount of space.
* Waveform does not provide better mobility than Astral Step.
* If Morphling shifted all of his strength to agility, he can be bursted down by Void Spirit before he can react.
* Doing an Ethereal Blade combo on Void Spirit is incredibly difficult, as Dissimilate and Astral Step can allow him to escape or dodge the projectile.

* Medusa cares less than other heroes about armor reduction, since Mana Shield blocks 70% of all damage without taking armor/magic resistance into consideration. This makes 60% of your Corrosive Haze ineffective until Medusa's mana is drained.