Days of Future Past

Put seven 4/4 artifact Sentinel creature tokens with flying onto the battlefield. Then destroy
up to seven tapped mutant creatures.
Flashback {8}{b}{b}{b} (You may cast this card from your graveyard for its flashback cost. Then exile it.)
Terminate one Sentinel -- terminate one thousand --
it makes no difference. Our numbers are too great. Eventually mutants, we will overwhelm you.