The Rider of Plague

Indestructible, reach, wither
Whenever creature dies, if it has one or more
-1/-1 counters on it, put that many -1/-1 on a
creature you don't control at the end of turn.
{2}{b}, {t} , Remove a -1/-1 counter from a
creature; The Rider deals damage equal to the
number of -1/-1 counters on permanents
to target creature.
The Riders power is equal to the amount of -1/-1
counters on permanents.