Moshu, Welcoming Recruiter

First strike, menace
Whenever Moshu, Welcoming Recruiter deals
combat damage to an opponent, you may discard
any number of cards. When you do, exile that
many attacking creatures with an adventure cost.
You may cast those cards this turn.
Each card in your graveyard with an adventure
cost has unearth. The unearth cost is equal to the
cards mana cost.