Kayn, shadow assassin

Shadow (This creature can block or be blocked by
only creature with shadow)
While Kayn, the shadow assassin it's on the battlefield you cant play kayn, the reaper.
Whenever Kayn, the shadow assassin deals
combat damage to a player or planeswalker
put a +1/+1 counter to each other assassin
you control.
"You let me in... So foolish!"