They give you speed through ramp and resilience through artifacts, with the caveat that they do not contribute to your devotion to any specific color a vital consideration for decks relying on Theros-style god cards or specialized mana costs
one of the most efficient green cards ever printed
Crescendo of War allows your opponents to continuously beat into each other, and dissuades them from attacking you since your creatures are bigger too Finally, Dawn Charm is sort of a catch all, with everything from a fog effect, to creature regeneration, to a white avoid fate
Otherwise, exile the top card of each opponent's library
So at worst you have a 6/6 samurai, but at best you hit a living weapon, job select card, For Mirrodin!, Meteor Sword, Embercleave, and the nasty Nazgl Battle-Mace