Sinidar, The Soul Eater

When this creature enters the battlefield,
If you haven't killed a creature,
Gain control of target creature it can't be killed
{t}{b/r}{b}{b} Gain control target creature with
Toughness 4 or more if it dies Deal 4
damage to target creature
{t}{4}{b}{b} Destroy all white or green creatures,
if you do put a +2+2 counter on target creature