Non-Elf creatures get -2/-2 until end of turn.

Menace

When Massacre Girl enters the battlefield, each other creature gets -1/-1 until end of turn. Whenever a creature dies this turn, each creature other than Massacre Girl gets -1/-1 until end of turn.

Creatures you control have wither.

Whenever a creature an opponent controls dies, if it had 0 or less toughness, you and that player lose 1 life and you draw a card.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)

I — Create a 2/3 red Demon Berserker creature token with menace.

II — Whenever a Berserker attacks this turn, you draw a card and you lose 1 life.

III — Add for each Berserker you control. Until end of turn, you don't lose this mana as steps and phases end.