Legion of Amestria

Create a number of 1/1 white Soldier creature tokens equal to your devotion to white.
Create an X/X blue Avatar creature token,
where X is your devotion to blue.
Flashback {3}{u}{u} (You may cast this card from your graveyard for its flashback cost. Then exile it.)
They will strike twice. First, to break you. Second, to clean up what's left.