example usage:
auto=life:thriceX
auto=@damaged(player):life:twicethatmuch
auto=life:twicetype:creature:mybattlefield
so to code cards like Debt to the Deathless
[card]
name=Debt to the Deathless
auto=@lifeloss(opponent):life:thatmuch controller
auto=life:-twiceX opponent
text=Each opponent loses two times X life. You gain life equal to the life lost this way.
mana={X}{W}{W}{B}{B}
type=Sorcery
[/card]