Tell me tell me,

It's a story about a bizarre love triangle between a student and his mentor. And their shared fascination. The student is a non human and the mentor is twice married. The object of their affection is ... like an Angel, but not quite.
She's a Valkyrie so, she doesn't age the same.
Gamleon ?
Most people would say he's a goat man.
Well, it just so happens that this particular goat man is now the richest creature. in any known land or empire. And he could, if he were so inclined. have anyone he wanted at his side.
But of course, it's her . His mentor just happens to beat him to the punch.