Kepler Buffet

{t}: Add {b} to your mana pool. Lose 1 life.
{t}: Add {g} to your mana pool. Gain 1 life.
{3}{t}: Kepler Buffet deals 2 damage to target
creature and 2 damage to you. If only {g} was
used to pay for this effect, Kepler Buffet deals
no damage to you.