Ranshi, Thoughtful Rage

Trample
When a creature dealt damage by Ranshi,
Thoughtful Rage dies, you may cast an Instant
or Sorcery with a converted mana cost X or less
from your graveyard without paying its mana
cost. X is equal to the amount of damage dealt.
Exile it after it resolves.
Whenever an opponent casts spell during your
turn, put a +1/+1 counter on Ranshi.