Brightsteel Colossus

Trample, indestructible
Dawn {w}{w}{w}{w} ---- When Brightsteel Colossus attacks, if you control 4 or more basic Plains, attacking creatures you control get +2/+2 and gain lifelink until end of turn. Untap those creatures.
If Brightsteel Colossus would be put into a graveyard from anywhere, reveal Brightsteel Colossus and shuffle it into its owner's library instead.