The Deck:

Commander:
Tasha, the Witch Queen

Creatures:
1 Dauthi Voidwalker
1 Gix, Yawgmoth Praetor
1 Halo Forager
1 Nashi, Moon Sage's Scion
1 Nightveil Specter
1 Opposition Agent
1 Thada Adel, Acquisitor
1 Thief of Sanity
1 Displacer Kitten
1 Gonti, Lord of Luxury
1 Grima, Saruman's Footman
1 Hostage Taker
1 Intellect Devourer
1 Xanathar, Guild Kingpin
1 Brainstealer Dragon
1 Diluvian Primordial
1 Elder Brain

Instants:
1 Pact of Negation
1 Brainstorm
1 Dark Ritual
1 Mystical Tutor
1 Swan Song
1 Counterspell
1 Cyclonic Rift
1 Drown in the Loch
1 Mana Drain
1 Outrageous Robbery
1 Siphon Insight
1 Fierce Guardianship
1 Force of Negation
1 Memory Plunder
1 Force of Will

Sorceries:
1 Ponder
1 Reanimate
1 Demonic Tutor
1 Maddening Cacophony
1 Fractured Sanity
1 Mnemonic Betrayal
1 Praetor's Grasp
1 Toxic Deluge
1 Windfall
1 Arcane Heist
1 Damnation
1 Stolen Goods
1 Talent of the Telepath
1 Bribery
1 Heartless Conscription

Artifacts:
1 Jeweled Lotus
1 Mana Crypt
1 Mana Vault
1 Sol Ring
1 Arcane Signet
1 Dimir Signet
1 Fellwar Stone
1 Grim Monolith
1 Talisman of Dominance
1 Chaos Wand
1 Thran Dynamo

Enchantments:
1 Mystic Remora
1 Animate Dead
1 Liliana's Talent
1 Cunning Rhetoric
1 King Narfi's Betrayal
1 Rhystic Study
1 Court of Locthwain
1 Treachery
1 Mind's Dilation

Planeswalkers:
1 Ashiok, Nightmare Muse

Lands:
1 Ancient Tomb
1 Cabal Coffers
1 Command Tower
11 Island
1 Morphic Pool
1 Polluted Delta
1 Prismatic Vista
11 Swamp
1 Underground Sea
1 Urborg, Tomb of Yawgmoth
1 Watery Grave

The Gameplan:

My opponents always have really cool cards.

This deck is all about stealing the cool stuff my opponents play.

Whether it be the field or the graveyard, nothing is safe from being stolen by this deck!