Ob Nixilis, the Adversary

Type line

Legendary Planeswalker — Nixilis

Oracle text

Casualty X. The copy isn't legendary and has starting loyalty X. (As you cast this spell, you may sacrifice a creature with power X. When you do, copy this spell. The copy becomes a token.) +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.

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.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.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."2022-04-29
• You can control exactly one legendary Ob Nixilis, the Adversary and any number of nonlegendary copies of Ob Nixilis, the Adversary.2022-04-29
• You may sacrifice only one creature to pay a spell's casualty cost, and you copy the spell only once.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.2022-04-29
• If you pay the casualty cost of a spell, the copy will resolve before the original spell.2022-04-29

Market price

$1.58