World War Hulk

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — The next red or green creature spell you cast this turn can be cast without paying its mana cost.
II — Put three +1/+1 counters on target creature you control.
III — Choose target creature you control. Until end of turn, double its power and toughness and it gains trample.