Bientok was minding his own business being a demon in the hell realm one day, when BAM he was yoinked right out of his home and into a pocket realm full of fae. Told he was to be the princess's familiar, which would then be able to take her right as queen of the fae in this swarm.
They told him this as if he had a choice or any say in the matter, while they started the ritual immediately after. Thus now, he's the queen of fae's familiar. And a magic reserve for her when she needs the extra boost.
Emo boy. Gives up a lot even before a fight is fully started, because he's been whipped by the fae into being fairly docile/just lets things happen because whats the point maaaan. The fae don't think highly of demons, and he's not allowed out of the pocket realm when the fae dock to explore/gather things, because he's a beastly little demon that can't be trusted with freedom.
Fae queen stole his name and gave him a new one when he refused to tell her his name when they demonnapped him from hell. His real name is Luca or Azure or something. There's a necklace/bracelet or some cosmetic jewelry piece he has/wears that he doesn't know is enchanted. The fae queen gave it to him and he's taken a liking to it, much to his annoyance. He can't quite tell why he likes it tho. Technically his name is locked in that necklace or bracelet or something and all he needs to do is crush it up and eat it to have his name return to him. Unfortunately the enchantment is so subtle only the greatest experts in enchantment and seal crafting can tell it's been tampered with/somethings inside it.
Detests bugs. Likes plants and books, and wants to see the sun again (the fae realm is always in perpetual state of moonlight night). He is physically unable to disobey or hurt his queen. She does tend to give him his space when she feels he's earned it/needs it.
He hangs out in the library of the fae pocket realm a lot. Been there a very long time cuz time doesn't progress in this realm. As the library is a quiet and solitary place for this emo demon boy, Bien has become quite the book nerd and enjoys reading every new book that gets brought into the small pocket realm by the fae when they go explore other worlds. He lurks around the fae queens castle library and has typically made it his living quarters, unless his queen demands he sleep within her chambers.
Knows lots of tidbits of info that he's gained from books over the eons of living in the fae realm. A lot of the info he gains from books are all over the various realms and worlds that exist. So his info may not always be realm specific or related to a conversation that's being talked about one thing, because it's a piece of info from an entirely different realm or merely a fantasy story from that realm. But he knows no difference and takes them as truth. Similarly if he's talking to a lifer, he's just going to assume they know of the thing he's talking about or that it's relevant for the same realm they are in. 'Because all lifers know about this life stuff yeah? Of course they know that a young zoomba shark from planet 36 nasgue accord #8 grows and drops 9037 teeth a day. Every lifer must know that! He read it in a book once. "have you ever seen one? What do they taste like?"