Commander Yamamoto

Vigilance
{x}{r}{r}{r}: Monstrosity X. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.)
When Commander Yamamoto becomes
monstrous, it deals X damage to each creature
and planeswalker.
"Prepare yourself. You will die with me in this
blazing inferno."
-Yamamoto Genryusai Shigekuni