Sidious, Lord of the Sith

Ward—Sacrifice a Jedi or pay 6 life.

When Sidious enters the battlefield, gain control of
target creature an opponent controls. It becomes a
Sith in addition to its other types. Put three +1/+1 counters on it. If that creature dies, exile Sidious and return it to the battlefield under your control at the beginning of the next end step.

At the beginning of your upkeep, if you control
more than two Sith, sacrifice Sidious.