Vannifar, Evolved Enigma

At the beginning of combat on your turn, choose one —
• Cloak a card from your hand. (Put it onto the battlefield face down as a 2/2 creature with ward {2}. Turn it face up any time for its mana cost if it's a creature card.)
• Put a +1/+1 counter on each colorless creature you control.

Conjurer's Closet

At the beginning of your end step, you may exile target creature you control, then return that card to the battlefield under your control.

Cloudstone Curio

Whenever a nonartifact permanent you control enters, you may return another permanent you control that shares a permanent type with it to its owner's hand.

Thassa, Deep-Dwelling

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature.
At the beginning of your end step, exile up to one other target creature you control, then return that card to the battlefield under your control.
{3}{U}: Tap another target creature.

Omniscience

You may cast spells from your hand without paying their mana costs.

Crystal Shard

{3}, {T} or {U}, {T}: Return target creature to its owner's hand unless its controller pays {1}.