Cadyrelle

While not actively a malicious soul, Cady is chronically lacking in any form of self awareness and as an immortal devil with a good millenia probably under his belt, his concept of time is not really the same as normal people.

So him leaving Elwyn with Rosalie and not showing up again for 10 years—it's not that he was intentionally abandoning his child, he's just never really raised any of them before and was never himself a child, so he's not really sure how that all works, and 10 years to a man who's lived centuries really isn't that long... Right?

Every now and then he returns to the Other Realm (not by choice), but what Cady finds truly interesting is the ever changing world of the living mortals. And so he drifts about, latching onto whichever gaggle of mortal life catches his interest like a cat with a new toy, until he grows bored and finds another.

Which is how he met Rosalie, Charity, and later Warlon—who, seeing these young dumb 20 somethings hanging out with a bonafide devil decided, hm! Perhaps should not leave these two unattended, and joined them in their misadventures. He and Cady eventually had something of a thing for a few years, before Warlon presented his masterpiece to the guild and dedicated himself to teaching.