Ontai,Creator of Planes

Mana doesn't empty from your mana pool as steps and phases end.
At the beginning of your upkeep, you gain 1 life for each {w} in your mana pool, scry X where X is the amount of {u} in your mana pool, target player loses 1 life for each {b} in your mana pool, Ontai deals X damage to target creature where X
is the amount of {r} in your mana pool, and give target creature +1/+1 until end of turn where X
is the amount of {g} in your mana pool.