Ninja Class

If an opponent being dealt combat damage causes
a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
{1}{u}{b}: Level 2
Creatures you control have skulk.
{2}{u}{b}: Level 3
Whenever a creature you control returns to your
hand, if it had counters on it, put those counters
on the next creature to enter the battlefield under
your control this turn.