This spell costs {X} less to cast, where X is the total power of creatures you control. Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Formidable — At the beginning of combat on your turn, if creatures you control have total power 8 or greater, target creature you control gains haste until end of turn. (It can attack and {T} no matter when it came under your control.)

This land enters tapped. {T}: Add {G}. {1}{G}: This land becomes a 3/3 green Ape creature with trample until end of turn. It's still a land. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Until end of turn, double target creature's power X times.

Monstrous Onslaught deals X damage divided as you choose among any number of target creatures, where X is the greatest power among creatures you control as you cast this spell.