Kazuki, Immortal Assassin

Deathtouch, Firststrike, Shroud
Undying (When this permanent is put into a
graveyard from the battlefield, if it had no +1/+1
counters on it, return it to the battlefield under its
owner's control with a +1/+1 counter on it.)
{1}: Remove a counter from target creature.
{t}: Destroy target creature.
{b}, {t}: Target creature gets -6/-6 until end of turn.
{b}{b}{b}, {t}: Give all creatures -15/-15 until end
of turn.