Well... about the reasons, Belleros is, and maybe it wasn't very clear in the concept, a miscievous brat. He's like a 15-16 years old human, he's powerful, and not very wise. He wants glory and great battles and journeys and adventures, ad he can't have all that in the Feywild, because the Eladrin have put a lot of prohibitions (like, not being able to leave) and because the Arkeion family is still shunned. So he ran, secretly from everyone.
Yes, it's a simple character concept. The character is very youn, very naive, in a sense, very pure. The idea is, one day he will have to face the truth of his heritage, which is, supposedly, something very heavy. That's why I decided to make him very, very light and easy-going in the beginning.