Sja-Anat, Dimir Betrayer

Lifelink, Hexproof,
Sja-Anat can't be blocked.
Whenever Sja-Anat deals combat damage
to a player, choose target permanent that player controls. You may pay X life, where
X is that card's CMC. If you do so, gain control of that permanent for as long as you control Sja-Anat.