Bolas's Citadel

You may cast up to one target instant card and/or up to one target sorcery card from your graveyard each with mana value X or less without paying their mana costs. If a spell cast this way would be put into your graveyard, exile it instead. If X is 10 or more, copy each of those spells twice. You may choose new targets for the copies.

Trample Whenever you cast a noncreature spell, this Vehicle becomes an artifact creature and gets +1/+1 until end of turn. Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Search your library and/or graveyard for a creature card with mana value X or less and put it onto the battlefield. If you search your library this way, shuffle. If X is 10 or more, creatures you control get +X/+X and gain haste until end of turn.

Return a creature you control to its owner's hand, then destroy all creatures.

Whenever a creature you control with deathtouch deals damage to a player or planeswalker, put a +1/+1 counter on that creature. −2: Create a 1/1 black Assassin creature token with deathtouch and "Whenever this token deals damage to a planeswalker, destroy that planeswalker."

T: Add C. 4, T: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Flying Whenever you cast an instant or sorcery spell that targets a creature you control, exile that card instead of putting it into your graveyard as it resolves. If you do, return it to your hand at the beginning of the next end step.

Destroy any number of target planeswalkers. Choose a planeswalker you control. Put two loyalty counters on it for each planeswalker destroyed this way.