An eccentric chimera demon born between dimensions; FYU is a loud and flippant trickster of sorts, if but ultimately functioning with absolutely WHOLESOME intentions at heart, honest!
His interests are in the "what ifs" of history, the pursuits of innumerable sciences, the capacity for mortals to evolve and surpass their limits—
With very unique roots, his unyielding durability and innate strength have grown to heights many mortals could only dream of—but for him, they're merely perks to guarantee he can survive the worst of anything his experiments throw at him!
In simple terms, FYU is a clone of his father with samples of his mother mixed in, and his father is every bit of power from across entire universes, timelines—a combination of all the strongest, most cunning and brutally efficient warriors from all over history, now used as a blueprint alongside the genius of an immortal outlaw who has successfully defied gods and fled their authority for eons.
FYU is their magnum opus, the answer to their home kingdom of the demon realm falling to the gods when the lot had grown fed up with their near reality-ending antics.
He's also completely, totally disinterested in pursuing the 'family business' of said antics.
This, of course, would've been a massive disappointment to them—had they not perished when he was very young.
This WAS a massive disappointment to his uncle who took on raising him, the last king of the demon realm—until a final scheme employed by him lead to a sort of 'spat' where FYU revealed he had no intention of carrying out the wishes of his family's desire for power and vengeance, ultimately leading in his uncle's demise.
Needless to say, FYU does not remember his family kindly.
And that wouldn't matter much to him—if they weren't literal time-benders, chronically escaping fate and higher divine powers with knowledge of forbidden time traveling.
At any moment, FYU lives in a hidden fear that his parents will come back—and for all the innate skill and physical capability literally built into his core, he won't have anything to do about it.
For being a clone of his father—renders him completely at the whims of him whenever within proximity, functioning no more than as if a second body to the man.
Living on his own now, he's free to pursue his interests in history and all that the universes have ever held as he sees fit—and, built as untouchably strong as he is, the gods are all but resigned to his whims, mostly finding it a relief that such a powder keg of problems only wishes to be a mild inconvenience at best.
All this is to say—that FYU is used to a life where people either regard him as a tool, a means to an end, or something entirely different than them. He's used to a certain degree of separation from other sentient beings, or temporary deals where they might tolerate his presence to give him some biological data should he get them something they want in return.
He is incredibly lonely, but he will never admit it
