Ob Nixilis of the Black Oath (27)

: Each opponent loses 1 life. You gain life equal to the life lost this way.
: Create a 5/5 black Demon creature token with flying. You lose 2 life.
: You get an emblem with ", Sacrifice a creature: You gain X life and draw X cards, where X is the sacrificed creature's power."
Ob Nixilis of the Black Oath can be your commander.