Omniknight/Counters

Bad against...

 * turns Omniknight into a walking creep, or completely takes out his buffed cores.
 * Doom also has access to Satyr Banisher's, which leaves enemies to few item counter builds or plays mistakes.


 * will purge Guardian Angel.
 * will deplete Omniknight's already small mana pool.
 * Invoker's many disables will keep Omniknight's team occupied until Guardian Angel times out.


 * can be used to time out Guardian Angel, giving Naga Siren's team an easy opportunity to counter-initiate.
 * Since doesn't affect magic immune units, it can be used to disable the rest of Omniknight's team while her team focuses on a single Repelled enemy.


 * 's AoE purge will remove Omniknight's buffs, although it cannot directly target a unit under Repel.


 * 's pure damage penetrates Guardian Angel's defense.
 * Outworld Devourer's intelligence steal is also devastating to Omniknight's already low mana pool.


 * will purge Omniknight's buffs from any ally who casts a single target spell against Razor.


 * All of Omniknight's abilities are valuable for Rubick to, and Omniknight has no throwaway ability to cover his last used spell.


 * will remove Omniknight's buffs.


 * takes Omniknight out of the fight completely.
 * are a great harass vs Omniknight during the laning stages of the game, since it doesn't aggro creeps & ignores his high base armor. It deals pure damage, which means it can also go through Guardian Angel.
 * Silencer's intelligence steal can also cause Omniknight to falter in the early phases as it reduces his ability to use his spells.

Others

 * In general, heroes with large magical AoE damage will fare well against Omniknight:, , , , etc..
 * Omniknight's teamfight impact is greatly reduced by heroes who can pierce his defensive buffs with disables, such as:, , , etc.
 * Omniknight's is vulnerable during the laning stage. Heroes such as and  can easily harass Omniknight out of a lane with their ranged slows and poison damage. Other heroes that pose a great threat are heroes with disables, such as  or, who can easily render Omniknight helpless, while also depleting his low mana pool.

Items

 * and other items that can prevent the casting of abilities makes Omniknight useless.
 * 's ability to purge a target of its buffs can become dangerous, as the effects of both Guardian Angel and Repel are both eliminated.
 * 's cyclone can purge Guardian Angel.

Good against...

 * Omniknight's healing prevents allies from dropping low enough for ; however, it can still go through all his buffs.
 * Axe also enjoys getting close to allied heroes in order to damage them with his, which can easily be punished by Purification or Guardian Angel.
 * Although Omniknight can easily deal with Axe in the later stages of the game, during the laning stages Axe can easily punish a support Omniknight.
 * Caution though, Omniknight's melee and short cast ranges make him an easy target for, which can easily turn the tide for the enemy.


 * s can be easily killed with.
 * Choas Knight's only defense against Omniknight, is being able to finish him off before he can get any spells off.


 * 's damage is blocked by Guardian Angel.
 * Be careful of her though!


 * is blocked by Guardian Angel.


 * is an excellent chance for Omniknight to use Purification.
 * Guardian Angel wastes 's duration entirely.

Others

 * Heroes that rely strongly on melee physical damage will fare badly against Omniknight's Guardian Angel.
 * Most heroes that rely heavily on magic damage and have low movement speed or mobility will have trouble against Omniknight, as he can slow them down with Degen Aura. Repel will also defend initiators against magical nukes.

Works well with...

 * A on Clockwerk while he's fighting inside  will turn the fight in Clockwerk's favor.


 * solves Omniknight's mana problems.


 * solves Omniknight's mana problems.


 * Use Repel on an enemy just before to prevent that enemy from becoming invulnerable and single him out for a quick kill.


 * A successful is an easy set-up for a Purification.
 * Omniknight can also negate the self-damage of with Repel. Use Repel on an enemy Pudge to prevent them from denying themself.


 * , and Purification can make for a very quick kill.
 * Repel can be used as an alternative to a Black King Bar, giving Mortred much needed protection against magical nukers.


 * Repel allows Shadow Fiend to channel in the midst of the enemy team without relying on.


 * let's Storm Spirit get close for an easy Purification.

Others

 * Omniknight works well with all heroes, although during the laning stages it's best to pair him with allies who can do most of the work or handle themselves without him, since he offers little to nothing during this stage.
 * In general, heroes that can blink into enemy formations gives Omniknight an opening to use Purification offensively.
 * Heroes that need a for spell immunity enjoy having Omniknight as an ally as he can either provide them more space to build the item, or allowing the would-be slot to be given to another item.

List of heroes that counter Omniknight, and list of heroes that work well with Omniknight.