Dwarven Alchemist

{b}{r},{t}: Flip a coin: If heads, deal four damage
divided between any number of creatures target opponent controls.
Your opponent takes damage equal to creatures
killed in this way. If tails, sacrifice 4 lands.
{r}{u},{t}: Flip a coin: If heads, all damage
opponents deal this combat phase to you and creatures you control is nullified.
If tails, tap half the creatures you control
(rounded up)