[@Liliya]
He is eighteen, and he indeed goes to the Halcyon High. Also, his mentor actually approved the whole idea because the team is basically the closest thing to stable and healthy relationships he has outside Nucleus. In fact, nowadays the two of them aren't really close for a reason that would be mentioned later. And no, nobody knows what he did before becoming a protege, and it's not he wants to talk about this topic, either. For everyone outside Nucleus and some of her fellow superheroes, he is simply a kid that popped out of nowhere and started helping. Ah, also, his career as a sidekick started when he was fifteen or so.