Ka'leam, the Fouled

Exploit (When this creature enters the battlefield, you
may sacrifice a creature.)
When Ka'leam, the Fouled exploits a creature,
destroy target creature you don't control. You
lose life equal to its mana value. If a creature was destroyed this way, put target creature card from
a graveyard onto the battlefield under your
control if its mana value is less than or equal to
the life you've lost this turn.