Megatron, Tyrant

More Than Meets the Eye {1}{r}{w}{b}
(You may cast this card converted for {1}{r}
{w}{b}.)
Your opponents can't cast spells during
combat.
At the beginning of each of your postcombat
main phases, you may convert Megatron. If
you do, add Colorless for each 1 life your
opponents have lost this turn.