Summon the Horde

As you cast Summon the Horde, flip a coin.
If you win the flip, put 15 red 1/1 Berzerker
creature tokens onto the battlefield. If you
lose the flip, put 6 red 1/1 Berserker creature
tokens onto the battlefield.
Flashback {8}{r}{r} (You may cast this card
from your graveyard for its flashback cost.
Then exile it.