Kuro, Solemn Samurai

The first time a creature dies under your control
each turn, each opponent loses 2 life.
The first time a creature dies under an
opponents control each turn, you gain 2 life.
"I don't know if you met Kuro, but he lost himself to
the Brazen Brigade. Tried to destroy Kairos, and
planned to bring down the Adventurer's Guild, kill
everyone in it, if he could. I think he went mad. He
certainly fell deep, deep into evil and despair."
- Kari Falk, to Neptune