Invigorating Waters

Convoke (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.)
Gain {x} life and put {x} +1/+1 counters on any
number of target creatures you control divided
as you choose.
Flashback -- {x}{g/w}{g/w}{g/w}{g/w} (You may cast this card
from your graveyard for its flashback cost. Exile it
after.).