Eirnad, Persistent Frost

Persist (When this creature dies, 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}{s}: Tap target creature. It doesn't untap
during its controller's untap step.
Whenever a creature an opponent controls
becomes tapped, put a +1/+1 counter on this creature.