Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control."

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

Spells and abilities your opponents control can't cause their controller to search their library.

-1: Target player mills four cards. Then exile each opponent's graveyard.

+2: Exile the top three cards of target opponent's library.

-X: Put a creature card with mana value X exiled with Ashiok, Nightmare Weaver onto the battlefield under your control. That creature is a Nightmare in addition to its other types.

-10: Exile all cards from all opponents' hands and graveyards.

Draw three cards, then put two cards from your hand on top of your library in any order.

Whenever you cast a blue spell, exile the top card of target player's library.

Whenever you cast a black spell, exile the top card of target player's library.

Your opponents can't cast spells with the same name as a card exiled with Circu, Dimir Lobotomist.

Return target permanent to its owner's hand. Its controller loses 3 life.

Transmute {1}{U}{B} ({1}{U}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Counter target spell.

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Destroy all creatures. They can't be regenerated.

Add {B}{B}{B}.

Shadow (This creature can block or be blocked by only creatures with shadow.)

If a card would be put into an opponent's graveyard from anywhere, instead exile it with a void counter on it.

{T}, Sacrifice Dauthi Voidwalker: Choose an exiled card an opponent owns with a void counter on it. You may play it this turn without paying its mana cost.

Look at the top three cards of target player's library. Exile any number of those cards, then put the rest back in any order.

Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Exile up to two target creatures you control, then return those cards to the battlefield under their owner's control.

Menace

Whenever Elder Brain 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.

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control and you create a Treasure token." (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Draw two cards, then discard two cards. Untap up to three lands.

Exile up to two target creatures you control, then return those cards to the battlefield under their owner's control.

Draw a card.

Devour Intellect -- When Intellect Devourer enters the battlefield, each opponent exiles a card from their hand until Intellect Devourer leaves the battlefield.

Body Thief -- You may play lands and cast spells from among cards exiled with Intellect Devourer. If you cast a spell this way, you may spend mana as though it were mana of any color to cast it.

+2: Look at the top card of target player's library. You may put that card on the bottom of that player's library.

0: Draw three cards, then put two cards from your hand on top of your library in any order.

-1: Return target creature to its owner's hand.

-12: Exile all cards from target player's library, then that player shuffles their hand into their library.

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)

Equip {0}

{T}: Add {C}.

{1}, {T}, Sacrifice Mind Stone: Draw a card.

Each opponent can't draw more than one card each turn.

-2: Look at the top four cards of your library. You may reveal a noncreature, nonland card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Counter target spell unless its controller discards their hand.

Transmute {1}{U}{B} ({1}{U}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Exile target artifact or creature. Its controller creates a 1/1 blue Bird creature token with flying.

Foretell {U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Until end of turn, target creature gets +1/+0 and gains lifelink and "When this creature dies, return it to the battlefield tapped under its owner's control."

Choose two target players. Each of them searches their library for a card, then shuffles and puts that card on top.

Draw a card. Scry 2.

Counter target noncreature spell unless its controller pays {2}.

({T}: Add {U} or {B}.)

Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)

Equip {1}

Each opponent exiles cards from the top of their library until that player has exiled cards with total mana value 20 or more.

If you would draw a card except the first one you draw in each of your draw steps, draw two cards instead.

Exile target permanent you control. Return that card to the battlefield under its owner's control at the beginning of the next end step. If it enters the battlefield as a creature, it enters with an additional +1/+1 counter on it.

You may activate loyalty abilities of Teferi, Master of Time on any player's turn any time you could cast an instant.

+1: Draw a card, then discard a card.

-3: Target creature you don't control phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

-10: Take two extra turns after this one.

Defender

Thing in the Ice enters the battlefield with four ice counters on it.

Whenever you cast an instant or sorcery spell, remove an ice counter from Thing in the Ice. Then if it has no ice counters on it, transform it.

When this creature transforms into Awoken Horror, return all non-Horror creatures to their owners' hands.

Umbris, Fear Manifest gets +1/+1 for each card your opponents own in exile.

Whenever Umbris or another Nightmare or Horror enters the battlefield under your control, target opponent exiles cards from the top of their library until they exile a land card.

At the beginning of combat on each opponent's turn, that player may exile a card from their graveyard. If the player doesn't, creatures they control can't attack you this turn.

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.