Ob Nixilis, the Adversary
Legendary Planeswalker — Nixilis
Casualty X. The copy isn't legendary and has starting loyalty X.
+1
: Each opponent loses 2 life unless they discard a card. If you control a Demon or Devil, you gain 2 life.
-2
: Create a 1/1 red Devil creature token with "When this token dies, it deals 1 damage to any target."
-7 : Target player draws seven cards and loses 7 life.
Tom Roberts
Magic Online Promos (PRM)
• #99687Rulings
As you cast a spell with casualty X, you choose whether to pay its casualty cost and what the value of X will be.
(wotc • 2022-04-29)
The copy of the spell is created on the stack, so it's not "cast." Abilities that trigger when a player casts a spell won't trigger.
(wotc • 2022-04-29)
Casualty N means "As an additional cost to cast this spell, you may sacrifice a creature with power N or greater." and "When you cast this spell, if a casualty cost was paid for it, copy it. If the spell has any targets, you may choose new targets for the copy."
(wotc • 2022-04-29)
You can control exactly one legendary Ob Nixilis, the Adversary and any number of nonlegendary copies of Ob Nixilis, the Adversary.
(wotc • 2022-04-29)
You may sacrifice only one creature to pay a spell's casualty cost, and you copy the spell only once.
(wotc • 2022-04-29)
The copied spell from Ob Nixilis, the Adversary's triggered ability copies exactly what is printed on Ob Nixilis, except its starting loyalty is equal to the chosen value of X and it isn't legendary. The copy becomes a token as it resolves.
(wotc • 2022-04-29)
If you pay the casualty cost of a spell, the copy will resolve before the original spell.
(wotc • 2022-04-29)
Printings
Rulings
As you cast a spell with casualty X, you choose whether to pay its casualty cost and what the value of X will be.
(wotc • 2022-04-29)
The copy of the spell is created on the stack, so it's not "cast." Abilities that trigger when a player casts a spell won't trigger.
(wotc • 2022-04-29)
Casualty N means "As an additional cost to cast this spell, you may sacrifice a creature with power N or greater." and "When you cast this spell, if a casualty cost was paid for it, copy it. If the spell has any targets, you may choose new targets for the copy."
(wotc • 2022-04-29)
You can control exactly one legendary Ob Nixilis, the Adversary and any number of nonlegendary copies of Ob Nixilis, the Adversary.
(wotc • 2022-04-29)
You may sacrifice only one creature to pay a spell's casualty cost, and you copy the spell only once.
(wotc • 2022-04-29)
The copied spell from Ob Nixilis, the Adversary's triggered ability copies exactly what is printed on Ob Nixilis, except its starting loyalty is equal to the chosen value of X and it isn't legendary. The copy becomes a token as it resolves.
(wotc • 2022-04-29)
If you pay the casualty cost of a spell, the copy will resolve before the original spell.
(wotc • 2022-04-29)