Mindslaver

{4}, {T}, Sacrifice Mindslaver: You control target player during that player's next turn. (You see all cards that player could see and make all decisions for the player.)

Time Sieve

{T}, Sacrifice five artifacts: Take an extra turn after this one.

Ashnod the Uncaring

Deathtouch
Whenever you activate an ability of an artifact or creature that isn't a mana ability, if one or more permanents were sacrificed to activate it, you may copy that ability. You may choose new targets for the copy. (Sacrificing an artifact for mana to activate an ability doesn't count.)