* All of Venomancer's abilities are decent choices for Rubick's Spell Steal. Stealing Plague Wards makes them apply Poison Sting as well.

* Dark Rift allows Underlord to transport allies from poison damage-over-time to the fountain.
* Underlord usually buys Pipe of Insight that gives a magic resistance to allies, inhibiting the damage from Venomancer abilities.

* Rubick is a potential counter to Bounty Hunter as he can steal his Track and use it against his invisibility, and also provide his team with more gold if the tracked hero is killed.

* In general, attacks of the melee heroes who are entirely reliant on dealing physical damage and/or have very little to no area-of-effect abilities will make Underlord tickle and will have no effect against him, and will be unable to ambush Underlord and his team if Underlord chooses to use Dark Rift to get to a designated point of the map: Phantom Assassin, Terrorblade, Troll Warlord, Drow Ranger, Phantom Lancer, Chaos Knight, Sven, Wraith King, Bounty Hunter, Alchemist, Templar Assassin, Nyx Assassin, Bane.

* In general, heroes with long cooldowns on their abilities or ultimate will struggle against the relentless pressure provided by Dark Rift or Fiend's Gate (Requires Aghanim's Scepter): Terrorblade, Dragon Knight, Omniknight.

* All of Omniknight's abilities are valuable for Rubick to Spell Steal, and Omniknight has no throwaway ability to cover his last used spell.
Additional:
* All Omniknight's abilities are perfect to steal:
* Purification can heal allies as well as damage enemies under the right circumstances. It is extremely useful since Rubick has no heal of his own.
* Heavenly Grace gives a strength bonus, status resistance, and health regeneration, which can help an ally or Rubick survive longer.
* Guardian Angel can turn the tide of battle by negating all physical damage, which is especially useful if the opposing team has physical attackers.

* 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 cause unique interactions on their own:
* Waveform is a damaging pseudo-blink, giving Rubick much needed mobility.
* Attribute Shift (Strength Gain) is a great ability for Rubick:
* The changes done by it are permanent even after losing the ability. Pumping all the agility into strength makes him much tankier. The armor loss due to reduced agility can be mitigated by cheap items like Medallion of Courage or Solar Crest.
* The extra strength allows Rubick to survive Morphling's Ethereal Blade - Adaptive Strike (Agility) combo.
* Beware when using Attribute Shift (Agility Gain)! Unlike Morphling, Rubick does not gain damage from it, since agility is not his primary attribute.
* Adaptive Strike (Strength) is a long-ranged stun.
* The true power of this ability is revealed when Attribute Shift (Strength Gain) has been stolen previously: it gives a 4 second ranged stun every 10 seconds, which greatly counters heroes with mobility, such as Morphling himself.
* All of Rubick's abilities break Linken's Sphere, a core item for Morphling.

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

* Heroes that reduce the damage that Marci can deal during her ultimate, like Razor, Rubick, Bane, Dragon Knight and Underlord.

* Heroes that reduce the damage that Marci can deal during her ultimate, like Razor, Rubick, Bane, Dragon Knight and Underlord.

* Firestorm will easily clear Chen's creeps.
* Pit of Malice will trap Chen and render him helpless.
* Atrophy Aura gives bonus damage to Underlord for each killed creep and weakens Chen's damage.
* Dark Rift can counter Chen's pushing attempts, and he has nothing to intercept it.

* Rubick can steal Death Ward easily as it is a channeled ability and then use it to turn teamfight to his advantage.
* However, a skilled Witch Doctor will toggle Voodoo Restoration immediately after placing his Death Ward to prevent that.
Additional:
* Every ability Witch Doctor has is useful when Rubick manages to steal any of them:
* Paralyzing Cask provides an additional disable apart from Telekinesis and also helps Rubick to farm.
* Voodoo Restoration provides utility by healing Rubick and his team, since he has no heal of his own.
* Maledict is a solid damage-over-time nuke, which can be devastating to the enemy team.
* And most importantly, Death Ward is one of the best teamfight spells in the game. It also requires channeling, which makes it easy for Rubick to steal. And when combined with Aghanim's Scepter, this can prove deadly to the enemy team.
* However, a skilled Witch Doctor will always toggle Voodoo Restoration while channeling Death Ward to prevent that.

* Fade Bolt reduces damage output of Anchor Smash.
* Ravage is an easy target to Spell Steal, so always be sure to use Anchor Smash immediately after Ravage when playing against a Rubick.
* Spells stolen by Rubick are potentially stronger due to the lack of cast animations, his talents, and his passive, Arcane Supremacy.

* Damage reduction from Atrophy Aura prevents Bloodseeker from killing targets and gaining his Thirst bonuses.
* Pit of Malice's area of effect catches Bloodseeker easily, negating his speed bonus during teamfights.
* Dark Rift allows Underlord to transport Ruptured allies to the fountain, rendering it useless.

* Everything she has is great in Rubick's kit:
* Crystal Nova deals crowd damage and slows enemies, also helps on farming.
* Frostbite helps Rubick locks down enemies, also is a decent farming ability.
* Freezing Field is a channeling ability and therefore can be stolen easily.
* Arcane Supremacy's Debuff Duration Amplification also benefits Crystal Nova and Frostbite greatly.

* All of Vengeful Spirit abilities are very good for Rubick to Spell Steal:
* Magic Missile provides an additional nuke/disable to pair with Fade Bolt and Telekinesis, respectively.
* Wave of Terror serves as a good scouting/armor reduction skill that Rubick and his team can benefit from.
* Nether Swap complements Rubick's mobility and pairs well with other mobility items he usually builds. He can also use it to save an ally from danger.

* Because of her need to get status items early to tank it up, Rubick can greatly reduce her damage early with Fade Bolt
* Her stationary nature and the slow cast time of her spells makes it easier for Rubick to steal Stone Gaze or Mystic Snake
* Aghanim's Scepter's Mystic Snake is often better used by Rubick than by Medusa

* Firestorm quickly kills all the treants and increases the Atrophy Aura passive.
* Pit of Malice can stop Teleportation channeling.
* Atrophy Aura greatly reduces Nature's Prophet's damage and he has no other ways of dealing damage.
* Dark Rift can counter split-pushing, which is something that Nature's Prophet relies a lot, and Nature's Prophet has very little solutions to intercept Dark Rift.

* In general, attacks of the melee heroes who are entirely reliant on dealing physical damage and/or have very little to no area-of-effect abilities will make Underlord tickle and will have no effect against him, and will be unable to ambush Underlord and his team if Underlord chooses to use Dark Rift to get to a designated point of the map: Phantom Assassin, Terrorblade, Troll Warlord, Drow Ranger, Phantom Lancer, Chaos Knight, Sven, Wraith King, Bounty Hunter, Alchemist, Templar Assassin, Nyx Assassin, Bane.

* Fiend's Grip is a powerful but channeled ability, making it useful and easy to Spell Steal and interrupt with Telekinesis.
* Stolen Fiend's Grip or Nightmare combined with Arcane Supremacy allows Rubick to disable Bane's allies for a longer period of time.
* As a natural Aghanim's Scepter carrier, Rubick can steal an upgraded Brain Sap and deal lots of damage to Bane's allies.

* Atrophy Aura decreases Troll Warlord's damage.
* Pit of Malice helps lock down Troll Warlord.
* Battle Trance disallows Troll from running out of both Firestorm and Pit of Malice.

* Firestorm's percentage damage can quickly demolish the Spirit Bear's high HP
* Pit of Malice will allow allies to easily kite Lone Druid due to his low mobility

* Rubick can turn around entire teamfights if he manages to steal Reverse Polarity.
* Shockwave allows Rubick to farm pretty fast together with Fade Bolt, and also deals decent AoE damage in teamfights.
* If Rubick steals Skewer, he can use Telekinesis to displace enemies and Skewer them away.
Additional:
* All of Magnus's spells are perfect for Rubick to steal, especially Reverse Polarity for a counter-initiation.
* Telekinesis is one of the best instant-disables in the game, completely ruining Magnus's initiation.

* Pit of Malice prevents Phantom Assassin from either escaping or engaging with Phantom Strike.
* Phantom Assassin's damage output is entirely physical, therefore Atrophy Aura is very hazardous for her in most of the stages, particularly since it also affects Coup De Grace, hindering Phantom Assassin's main source of damage.
* Without proper items and any area-of-effect ability/item, Phantom Assassin cannot stop Underlord and his team to escape with Dark Rift, nor she can intercept them if Underlord chooses to teleport on any area of the map, though she can still kill a unit that is a target for Dark Rift if she is quick enough and if it's in her range.
Additional:
* Pit of Malice prevents Phantom Assassin from either escaping or engaging with Phantom Strike.
* Phantom Assassin's damage output is entirely physical, therefore Atrophy Aura Atrophy Aura is very hazardous for her in most of the stages, particularly since it also affects Coup De Grace Coup de Grace, hindering Phantom Assassin's main source of damage.
* Without proper items and any area-of-effect ability/item, Phantom Assassin cannot stop Underlord and his team to escape with Dark Rift, nor she can intercept them if Underlord chooses to teleport on any area of the map, though she can still kill a unit that is a target for Dark Rift if she is quick enough and if it's in her range.

* Fissure has a shorter cast time in Rubick's hands, making it a nice ability to either initiate or interrupt enemy ganks from a long distance.
* Though Echo Slam isn't as powerful for the lack of Aftershock on Rubick, the damage can still be massive on enemies.

* If Rubick can use Spell Steal to take Nethertoxin, he will be able to disable Corrosive Skin, reducing much of Viper's durability.
* He can also steal Viper Strike, which can be used to hinder a hero on your team (or multiple heroes, if Rubick has Aghanim's Scepter).

* Telekinesis has a longer range than the AoE of Black Hole for the purposes of cancelling it.
* All of Enigma's spells are useful to Spell Steal.
* Malefice is useful for interrupting channeling spells or long cast animations.
* Demonic Conversion can be used to push or counter-push a lane.
* Midnight Pulse is useful to block an area or for team fights.
* Black Hole is very easy to steal, as it is a channeled ability. It's also one of the best ultimate abilities for team fights, and it can easily turn the fight around for the enemy team.
Additional:
* Everything Enigma has is something Rubick will like:
* Malefice helps with interrupting channeling spells in case Telekinesis is off cooldown.
* Demonic Conversion helps with pushing or counter-pushing a lane.
* Midnight Pulse is great for blocking off areas or just doing steady damage in teamfights.
* Black Hole is one of the best spells for teamfights, and could easily turn a losing one around.
* Black Hole also requires channeling, making it an easy steal for Rubick because he usually stays back in a teamfight, making it hard to catch him with Black Hole.
* Telekinesis can break Enigma's Black Hole fairly easily.
* Fade Bolt counters early push strategy of Enigma's waves of Eidolons.
* Spell Steal pierces spell immunity, so Enigma can't prevent Rubick from stealing Black Hole by activating Black King Bar.

* All of Invoker's abilities scales with his level, thus Rubick possesses great potential in late game by owning any of Invoker's arsenal.
* Fade Bolt counters early push from Forge Spirit.

* All his abilities is decent in Rubick's kit:
* Frost Blast allows Rubick to harass and constantly slow down enemies.
* Frost Shield increases Rubick's as well as his allies' and tower's survivability to physical attacks.
* A well-timed Chain Frost can be devastating to the enemy team.

* Rubick will find all Lina's abilities useful:
* Dragon Slave provides a good way to clear creep waves and allows Rubick to deal tons of magical damage in teamfights.
* Light Strike Array gives Rubick a solid area stun, which is easy to set up right after Telekinesis.
* Laguna Blade gives Rubick a massive damage boost and great solo kill potential.

* 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.

* All of Lion's abilities are worth stealing with Spell Steal.
* Arcane Supremacy makes the disabling spells stolen from Lion very useful, allowing you to disable enemies for an extremely long time during fights or ganks.
* By using Telekinesis, Rubick can easily catch Lion out. Without any escape mechanism, Lion is helpless, especially when ganked.
Additional:
* Everything Lion has is great in Rubick's kit, further amplified by Arcane Supremacy:
* Earth Spike adds a second bit of crowd control and some damage.
* Mana Drain solves a lot of Rubick's mana issues.
* Hex is one of the strongest single-target lockdowns in the game.
* Finger of Death is one of the best magical nukes in the game.

* Firestorm and Pit of Malice are very disruptive in team fights, completely matching Mars especially since it can all be cast inside Arena Of Blood and also does percentage-based magical damage, negating Bulwark.
* Dark Rift can save any allies of Underlord trapped in Arena Of Blood.
* Atrophy Aura allows Underlord to lane against Mars quite well since he does not have the best base damage during the early game.
* Underlord is a common carrier of both Pipe of Insight and Mekansm/Guardian Greaves, allowing his team to combat Mars in the mid to late game.

* Fade Bolt can hinder Jakiro's early pushing power by clearing creep waves.
* All of Jakiro's spells are great for Rubick to Spell Steal.
* Ice Path is a great spell for Rubick so steal, since Rubick has no cast time on stolen abilities, making Rubick's version of Ice Path much more reliable than Jakiro's.
* Macropyre is a great way for Rubick to farm.

* Pit of Malice can be cast in the path of Spirit Breaker's Charge of Darkness to cancel it.
* Dark Rift provides a way to escape from a gank for Underlord and his teammates.

* In general, melee heroes without blink mechanisms or spell immunity will have a hard time positioning against Pit of Malice: Sven, Tiny, Wraith King, Dragon Knight, Meepo, Doom, Bounty Hunter, Dark Seer, Undying, Alchemist, Legion Commander.

* In general, melee heroes without blink mechanisms or spell immunity will have a hard time positioning against Pit of Malice: Sven, Tiny, Wraith King, Dragon Knight, Meepo, Doom, Bounty Hunter, Dark Seer, Undying, Alchemist, Legion Commander.

* In general, attacks of the melee heroes who are entirely reliant on dealing physical damage and/or have very little to no area-of-effect abilities will make Underlord tickle and will have no effect against him, and will be unable to ambush Underlord and his team if Underlord chooses to use Dark Rift to get to a designated point of the map: Phantom Assassin, Terrorblade, Troll Warlord, Drow Ranger, Phantom Lancer, Chaos Knight, Sven, Wraith King, Bounty Hunter, Alchemist, Templar Assassin, Nyx Assassin, Bane.

Additional:
* Atrophy Aura reduces Terrorblade's damage significantly, even during Metamorphosis.
* Firestorm deals significant damage to Terrorblade and his illusions from a safe distance
* Pit of Malice can keep Terrorblade and his illusions under control
* Dark Rift and Fiend's Gate (requires Aghanim's Scepter) can bail out Underlord's team away from a bad engagement against a Terrorblade under Metamorphosis
* Likewise, either Dark Rift or Fiend's Gate can be used to quickly move Underlord's team to the frontlines, to strike Terrorblade's team during Metamorphosis' 155 seconds of cooldown

* In general, attacks of the melee heroes who are entirely reliant on dealing physical damage and/or have very little to no area-of-effect abilities will make Underlord tickle and will have no effect against him, and will be unable to ambush Underlord and his team if Underlord chooses to use Dark Rift to get to a designated point of the map: Phantom Assassin, Terrorblade, Troll Warlord, Drow Ranger, Phantom Lancer, Chaos Knight, Sven, Wraith King, Bounty Hunter, Alchemist, Templar Assassin, Nyx Assassin, Bane.

* Heroes with powerful rooting abilities will disable most of Pangolier's skills, a bonus point if it pierces spell immunity since it will also be able to stop Pangolier during his Rolling Thunder: Treant Protector, Meepo, Crystal Maiden, Dark Willow, Underlord, Naga Siren

* In general, attacks of the melee heroes who are entirely reliant on dealing physical damage and/or have very little to no area-of-effect abilities will make Underlord tickle and will have no effect against him, and will be unable to ambush Underlord and his team if Underlord chooses to use Dark Rift to get to a designated point of the map: Phantom Assassin, Terrorblade, Troll Warlord, Drow Ranger, Phantom Lancer, Chaos Knight, Sven, Wraith King, Bounty Hunter, Alchemist, Templar Assassin, Nyx Assassin, Bane.

* In general, melee heroes without blink mechanisms or spell immunity will have a hard time positioning against Pit of Malice: Sven, Tiny, Wraith King, Dragon Knight, Meepo, Doom, Bounty Hunter, Dark Seer, Undying, Alchemist, Legion Commander.

* In general, heroes with long cooldowns on their abilities or ultimate will struggle against the relentless pressure provided by Dark Rift or Fiend's Gate (Requires Aghanim's Scepter): Terrorblade, Dragon Knight, Omniknight.

* Heroes with strong team-fight abilities (especially ultimates) like Tidehunter, Brewmaster, Death Prophet, etc.

* In general, melee heroes without blink mechanisms or spell immunity will have a hard time positioning against Pit of Malice: Sven, Tiny, Wraith King, Dragon Knight, Meepo, Doom, Bounty Hunter, Dark Seer, Undying, Alchemist, Legion Commander.

* Heroes with strong team-fight abilities (especially ultimates) like Tidehunter, Brewmaster, Death Prophet, etc.

* In general, attacks of the melee heroes who are entirely reliant on dealing physical damage and/or have very little to no area-of-effect abilities will make Underlord tickle and will have no effect against him, and will be unable to ambush Underlord and his team if Underlord chooses to use Dark Rift to get to a designated point of the map: Phantom Assassin, Terrorblade, Troll Warlord, Drow Ranger, Phantom Lancer, Chaos Knight, Sven, Wraith King, Bounty Hunter, Alchemist, Templar Assassin, Nyx Assassin, Bane.

* All of Treant Protector's abilities are worth stealing, and Rubick is able to cast them with no animation time.

* Rubick can use Spell Steal to steal Astral Imprisonment, and if Rubick gets Aghanim's Scepter he gets 2 charges of it. This can overpower Outworld Destroyer in team fights.
* Rubick can also steal Sanity's Eclipse against Outworld Destroyer's teammates.

* Firestorm will destroy Refraction charges very quickly.
* Firestorm will hit Templar Assassin while under the effects of Meld Meld.
* Templar Assassin has a hard time maneuvering around Pit of Malice.

* Pit of Malice prevents Riki from casting Blink Strike. or Tricks of the Trade.
* Atrophy Aura reduces Riki's damage.
* Firestorm can be used to harrass Riki in lane.

* Despite most Kunkka players depending on their immense physical damage, his spells provide a lot of utility for Rubick:
* Torrent is very easy to land when paired with Telekinesis.
* X Marks the Spot can potentially be more effective in Rubick's hands due to his tendency to increase his cast range with his talents and items.
* Ghostship, paired with Telekinesis, allows Rubick to land it very easily without requiring Torrent or X Marks the Spot.

* 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.

* All of Winter Wyvern's spells are generally good for Rubick to steal:
* Arctic Burn provides bonus attack range, night vision and burn.
* Splinter Blast makes farming and pushing efficient while also slowing down the enemies.
* Cold Embrace can heal an ally and protect them against physical attacks.
* Winter's Curse can be stolen by Rubick and use it against herself or her own team.

* Atrophy Aura's percentage-based damage reduction greatly diminishes Legion Commander's overall damage output, even if she has won many Duels.
* Dark Rift can be used to save Underlord or his allies from Duels if properly timed.
Additional:
* Atrophy Aura makes it hard for Legion Commander to win Duels.
* Dark Rift can be used to save Underlord and his allies from a Duel.

* In general, melee heroes without blink mechanisms or spell immunity will have a hard time positioning against Pit of Malice: Sven, Tiny, Wraith King, Dragon Knight, Meepo, Doom, Bounty Hunter, Dark Seer, Undying, Alchemist, Legion Commander.

* Lucent Beam is a solid magic nuke.
* Eclipse can cause massive damage if cast in the right time.
* Rubick has a good chance to steal Eclipse for Luna has only two cast abilities.
* Aghanim's Scepter greatly increased the effectiveness of the ability, including more damage as well as longer cast range. In addition, it allows him to cast it on another hero so Rubick doesn't have to get close to the enemy team in teamfights.

* If Rubick steals Reaper's Scythe, he can turn the powerful ultimate back against Necrophos' team. Even his other spells are useful in Rubick's hands, giving him a sustain or a weak initiation/protection tool.