Arvinox isn't a creature unless you control three or more permanents you don't own. At the beginning of your end step, exile the bottom card of each opponent's library face down. For as long as those cards remain exiled, you may look at them, you may cast permanent spells from among them, and you may spend mana as though it were mana of any color to cast those spells.

{4}, {T}: Target opponent exiles cards from the top of their library until they exile an instant or sorcery card. You may cast that card without paying its mana cost. Then put the exiled cards that weren't cast this way on the bottom of that library in a random order.

Menace Whenever this creature attacks a player, exile all cards from that player's hand, then they draw that many cards. You may play lands and cast spells from among the exiled cards for as long as they remain exiled. If you cast a spell this way, you may spend mana as though it were mana of any color to cast it.

Devour Intellect — When this creature enters, each opponent exiles a card from their hand until this creature leaves the battlefield. Body Thief — You may play lands and cast spells from among cards exiled with this creature. If you cast a spell this way, you may spend mana as though it were mana of any color to cast it.

You may cast target instant or sorcery card from an opponent's graveyard without paying its mana cost.

Target opponent exiles the top X cards of their library face down. You may look at and play those cards for as long as they remain exiled. If you cast a spell this way, you may spend mana as though it were mana of any type to cast it.

Look at the top two cards of target opponent's library. Exile one of them face down and put the other on the bottom of that library. You may play the exiled card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast that spell. Flashback {1}{U}{B}

Flying Whenever this creature deals combat damage to a player, look at the top three cards of that player's library, exile one of them face down, then put the rest into their graveyard. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast that spell.

{U/P}: Change a target of target spell or ability to this creature. ({U/P} can be paid with either {U} or 2 life.)

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.) Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

+1: Up to two other target planeswalkers you control phase out at the beginning of the next end step. (Treat them and anything attached to them as though they don't exist until your next turn.) −2: For each opponent, return up to one target nonland permanent that player controls to its owner's hand. −7: Target artifact you control becomes a 9/9 Construct artifact creature and gains vigilance, indestructible, and "This creature can't be blocked."

+2: Draw a card. Each player mills two cards. −5: Put target creature card from a graveyard onto the battlefield under your control. −11: Gain control of all creatures target opponent controls.

Flying, deathtouch When this creature enters, draw a card.

Flying, deathtouch Whenever you cast your first spell during each opponent's turn, look at the top card of that player's library, then exile it face down. You may play that card for as long as it remains exiled, and mana of any type can be spent to cast it.

Add {B}{B}{B}.

{1}, {T}: Add {U}{B}.

{T}: Add one mana of any color in your commander's color identity.

({T}: Add {U}.)

Counter target spell.

When this artifact enters, exile target card from a graveyard. {1}, {T}, Exile this artifact: Exile all cards from all graveyards, then draw a card.

Counter target noncreature spell.

Consuming Aberration's power and toughness are each equal to the number of cards in your opponents' graveyards. Whenever you cast a spell, each opponent reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

Each opponent mills fourteen cards. Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.) When you cycle this card, each opponent mills four cards.