Oh, and DS, your creature just makes life gain exceptionally good, since it does not prevent life gain, but only neutralizes it and makes you take that much damage, as well as potentially clearing the board.
It's not supposed to be good, just representative/amusing. The general idea was "fuckthis, burn everything", and "screw you guys, I'm going home"
I'd probably never actually play the damn thing (unless I was comboing it with cards that make opponents gain life, like nature's claim or swords to plowshares).
If I wanted to make something along the same lines only good it would be more like:
1RR
Darthstabber
Creature - Human Wizard Berserker
Haste
If an opponent would gain life you may sacrifice
Darthstabber, if you do, that life gain is prevented and Darthstabber deals damage to each player equal to the amount of life the opponent would have gained.
2/2