Brace The Gate!

(As a Siege enters, choose an opponent to protect it.
You and others can attack it. When it it is defeated,
exile it, then cast it transformed [7 HP].
When this enters create 3 1/1 white human
soldiers with Haste, sacrifice them at
the beginning of your next upkeep.
Players create a 1/1 white human soldier
token with Vigilance for each 1 damage they deal
to this Siege.