Grievous, Jedi Hunter

Double Strike, Menace
Whenever a planeswalker is destroyed put a +1/+1 counter on Grievous, Jedi Hunter
When this creature attacks, if there is a +1/+1 counter on it, it gets +2/+0 until end of turn.
When this creature blocks, if there is a +1/+1 counter on it, it gets +0/+2 until end of turn.