Magnus provides Slark with Empower, which greatly amplifies his farming speed, allowing him to get to his first couple of items consistently so he can start rolling the game. RP covers Slark's lack of hard Crowd Control and makes up for his teamfight pressence greatly. Magnus can Shockwave and Skewer away any targets that are trying to stick to Slark so he can retreat safely and heal up with Barracuda.

Omniknight allows Slark to stick on targets and build up as many Essence Shift stacks as possible, without having to retreat at all potentially. He can give him a Debuff Immunity from most spells and Magic Resistance with Repel, while also protect him from Physical damage with Guardian Angel. Slark likes sticking to his targets with Pounce, making him a great target for Purification. All and all, Omni allows Slark to go fully ham with his heavy defensive kit.

The 2 pair well together in lane as they are melee/ranged. Fortune's End can set up pounce, while Fate's Edict provides him with much needed Magic Resistance. Purifying Flames' damage can be offset by Barracuda in lane to quickly heal Slark back up and False Promise is an all purpose save button for him to keep getting Essence Shift stacks. All and all, Oracle allows Slark to go fully ham with his heavy defensive kit.

Dark Ascension turns day into night making it easier for Slark to disengage fights and hide out of sight in order to heal up with Barracuda - this is further amplified by the unobstructed vision from Dark Ascension as Slark can use the perfect information he's provided with to run circles around his opponents until he is ready to re-engage. Slark is one of the few heroes in DOTA with enhanced night vision and is significantly stronger as darkness engulfs the map.

Baraccuda allows Slark to determine whether he is being seen by his enemies, either by an invisible opponent or an Observer Ward - Lightning Bolt reveals invisibility, including Wards, allowing Zeus and Slark to scour the map and remove all enemy vision, giving them and their team a significant advantage. Depth Shroud (Aghanim's Shard Upgrade) is an amazing save for Zeus if he gets gone on, while Pounce is a long duration leash that can hold opponents down for Zeus to get multiple volleys of his spells of.

Dark Pact is a low cooldown Strong Dispel, which can dispel Enfeeble, Nightmare and even Fiend's Grip. Additionally, his Aghanim's Shard Depth Shroud can be used on any of his teammates during Nightmare or Fiend's Grip to provide sustain and protect them from any single target damage.

Dark Pact is a low cooldown Strong Dispel, which can dispel Flaming Lasso, Flamebreak's DOT as well as remove Sticky Napalm Stacks consistently. Pounce provides a reliable lockdown for Batrider to mitigate his mobility and Shadow Dance and Depth Shroud prevent Flaming Lasso from being cast on anyone under their effects.

Slark's Dark Pact dispels Searing Chains. Pounce provides strong lockdown for Ember, which can be further upgraded with Aghanim's Scepter to extend it's duration. Slark's best defensive mechanics are Shadow Dance and Depth Shroud, which prevent Ember from applying Searing Chains or connecting with Sleight of Fist, while giving him enough sustain to survive trough Flame Guard and Fire Remnants.

Dark Pact is a low cooldown ability that can dispel Track and almost matches Tracks's cooldown, giving Slark a reliable way of dealing with it. Pounce can leash BH during Shadow Walk, although without providing vision of him. Shadow Dance and Depth Shroud prevent Slark and any of his allies from being targeted by Shuriken Toss or it's bounces even while Tracked.

Slark's Essence Shift steals stats directly from Spectre and does't get mitigated by Dispresion in any way. Slark's various sources of sustain (Barracuda, Shadow Dance, Depth Shroud - Aghanim's Shard Upgrade) and Dark Pact being a low-cooldown dispel for Spectral Dagger gives Slark all the tool he needs to deal with Spectre.

Death Pulse, Hearthstopper Aura and Death Seeker (Aghanim's Shard Upgrade) can affect Slark during Shadow Dance and Depth Shroud (Aghanim's Shard Upgrade), which are his main defensive tools. Dark Pact does not dispel Reaper's Scythe and Ghost Shroud prevents Slark from attacking Necro and gaining Essence Shift stacks.

Rupture damages Slark during Pounce and makes it more difficult for him to play in and out of fights as eventually Thirst will reveal him and prevent him from healing with Barracuda. Blood Rite and Blood Mist (Aghanim's Scepter upg) can damage Slark during Shadow Dance and Depth Shroud due to it's AOE property.

Despite Dark Pact being able to dispell both Aftershock and Fissure's stuns the sheer amount of constant AOE control that Earthshaker provides simply overwhelms Slark as they are able to affect him during Shadow Dance and Depth Shroud.

Both Black Hole and Midnight Pulse can affect Slark despite his heavy defensive kit. Dark Pact does not dispel either, while Shadow Dance and Depth Shroud (Aghanim's Shard upgrade) do not prevent their effects due to them being AOE, giving Enigma a reliable way of locking down Slark . Black Hole can suck Slark back in as he Pounces and Midnight Pulse can destroy a large are of trees preventing him from hiding to heal up with Barracuda.

Leshrac's abundance of AOE damage allows him to damage Slark during his core defensive mechanims - Shadow Dance and Depth Shroud. Slark's low Strength gain makes him an easy target for Lesh in the early and mid game, before Slark farms up some tanky items and often finds himself run down by Lesh.

Crippling Fear cares little about Dark Pact as it does not get dispelled by it - this prevents Slark from getting of his highest impact spells, which are also his main survivability tools: Shadow Dance and Depth Shroud (Aghanim's Shard upgrade); as well as limiting his mobility due to him not being able to cast Pounce and get away. Dark Ascension's unobstructed vision makes it a nightmare for Slark to disengage a fight and hide somewhere in order to heal up with Barracuda.