Ogre, Vicious Steed

Whenever you cast an instant or sorcery spell, put +1/+1 counters on Ogre, Vicious Steed, equal to the spell's mana cost.
Remove 4 +1/+1 counters from Ogre,
Vicious Steed, Regenerate Ogre, Vicious Steed, or Razzil Darkbrew
Partner with Razzil Darkbrew