Kharn, the Betrayer

Haste, First Strike, Vigilance
At the beginning of combat on each player's
turn, that player gains control of Kharn.
Kharn attacks each combat if able.
At the beginning of your end step, sacrifice 3
creatures and Kharn deals 8 damage to you
unless a creature dealt damage by Kharn died
this turn.
{p/r}{p/r}: Kharn gains +2/+0 until the end
of your turn.