10 Doctor Strange Fates Worse Than Death
4. Succumbing To The Whims Of Nightmare
When you're the Master of the Mystic Arts tasked with keeping some of the darkest forces in the multiverse from destroying all of reality, getting a good night's sleep isn't easy. Strange may be an all-powerful sorcerer, but he's still a human being who needs to rest, and this can be a problem.
Sleeping puts him at risk of all sorts of things, so he has come up with a way of dealing with this problem over the years. Instead of saying his prayers before going to bed every evening, Strange weaves some magic and enchants himself during sleep, which protects him.
This is a great way for him to stay safe (and sane), but it only works for one sleep cycle, so if he gets tired or knocked out, he's vulnerable to all manner of evil entities, the worst of which is definitely Nightmare. In the comics, Nightmare is a Fear Lord who rules over the Dream Dimension.
Succumbing to the whims of Nightmare could leave a person completely insane, or he could take someone's astral projection and trap them in his realm. He's immortal and all-powerful, so it's definitely in Strange's best interest to say his spell before bedtime.