Band Together Against...

Foretell {p/w}{p/b} & Battle (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) [2 HP]
When this enters the battlefield each player
may search their library for a Planeswalker
card & add it to their hand. When destroyed
Planeswalkers cost {2} less until end of turn.