Julian, Enraged Behemoth

Trample
Julian gets +1/+1 for each rage counter on it
Julian cannot attack unless it has 2 or more Rage counters on it
At the beginning of your upkeep and whenever an opponent casts a spell, put a rage counter on Julian
{t}{g}{u}{r}: Julian deals damage equal to its power to target creature or planeswalker, put a stun counter on it and then remove all rage counters from Julian