So, Alverith Tyvan is the “Chosen One” archetype, I know — your Luke Skywalkers, your Aangs, your Links... but I think I’ve made him rather distinct, in his own way. He is the major linchpin in a world-ending conspiracy; without him, no “paradise on earth” according to those that caused his existence in the first place. He doesn’t know where he’s actually from — he thinks he’s a Slymouthian human orphan raised in a prestigious military academy. His earliest memory only goes back to age ten. The truth is much worse than you can imagine.

Big "protagonist" energy.

Early on, he’s arrogant. Properly arrogant — sharp-tongued, dismissive, a bit of a prince. He’s the guy who looks at your swordwork and tells you a twelve-year-old cadet could do better, and he genuinely thinks he’s being charming when he says it. But even at his most pompous, there’s a softness he can’t quite hide. He loves fishing, keeps a journal full of surprisingly beautiful sketches and eloquent handwriting, and has this naturalist’s fascination with the world around him. The first real crack in the princely facade is him letting his companion Valdal — a halfling inventor he initially looked down on — look through that journal.

Later after he finds out about his true nature, he really starts getting existential and views himself as an abomination that who just borrowed everything about himself from his... past iteration. 

He genuinely comes to love the people around him, but promises of power and to really fix things really start getting into his head. How long will it be until he starts viewing his friends at tools?

He would sound posh, but not absurdly so. He can be a smart alec sometimes, and loves poking at Valdal and Franziska especially. I'd also think Welsh could work with him too.