Yasuo, The Unforgiven

First strike

When an opponents creature is stunned or
removed from the battlefield by non-lethal
means, deal 2 damage to it.

Level up - When you've stunned or returned 5 or
more creatures this game, give Yasuo +1/+1 and
"When an opponents creature is stunned or
removed from the battlefield by non-lethal means,
deal damage to it equal to Yasuo's power."