The Faction Dragon [Unknown Event]

Flying

If The Faction Dragon is your commander, choose a faction during deckbuilding. This card's mana cost is the faction's mana symbols. (for example, if you choose Abzan, it costs WBG.)

Spells you cast with the chosen faction's watermark cost 1 less to cast.

Other creatures you control with the chosen faction's watermark get +1/+1.