Alazif is basically a sentient grimoire—the actual physical embodiment of the Forbidden Grimoire, a book stuffed with some seriously dangerous magic spells. For hundreds of years, he's been locked away in the Demon King Castle's library, sealed tight because, well, ancient forbidden magic tends to need that kind of security.
The whole setup was supposed to go like this: he'd eventually wake up to help humanity fight off demons and save the day. Pretty standard hero's journey stuff. Except that's not remotely what happened. Princess Suya accidentally woke him up one day, and instead of being pumped about finally getting to be useful, she's got exactly one thing on her mind—sleep magic. That's it. Not world-saving, not demon-slaying. Just spells to help her get some decent rest.
Alazif's left pretty confused by the whole situation, honestly. He's an ancient, powerful magical artifact who spent centuries waiting for his grand purpose, only to find himself saddled with a princess who couldn't care less about the whole "saving humanity" angle and just wants to catch some Z's.
Content compiled by AnimeList.moe from publicly available sources.