Doom Master

Command- When this creature enters or if you choose this creature as your commander choose this creature color(s). ( This Creature enters as the chosen colors, including commander identity )
{1}Place a -1/-1 Counter on target creature .

When you place a -1/-1 counter a creature you control target player lose 2 life
When you place -1/-1 counter a creature you don't control, you lose 2 life