Whenever an opponent draws a card, Ob Nixilis, the Hate-Twisted deals 1 damage to that player.
−2: Destroy target creature. Its controller draws two cards.
If Ob Nixilis leaves the battlefield before his last ability resolves, most likely because he only had 2 loyalty when you activated the ability, his first ability won't exist to trigger when the creature's controller draws two cards.
03-05-2019
wotc
If the target creature is an illegal target by the time Ob Nixilis's last ability tries to resolve, the ability doesn't resolve. No player draws two cards. If the target is legal but not destroyed (most likely because it has indestructible), its controller does draw two cards.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.
Yongjae Choi2022-12-02
