Grey Havens

As Grey Havens comme into play, you may pay 2 life. If you don't, Grey Havens comes into play tapped.
{t}: add {w} or {g} to your mana pool.
{g/w}, {t}: Creatures you own that aren't on the battlefield gain convoke until end of turn. (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)