Gabriel is very shy and pacifistic. He's always stuttering, soft-spoken and usually stays quiet, but the times that he does speak are usually when he shines. Sadly the only time this happens is when he's upset or angry. But usually he's seen not talking, keeping to himself and keeping a bottle on his emotions. He'd rather not end up like his father, thank you.
He looks exactly like Sephiroth, right down to the long silvery hair and impossible bangs. Not to mention the weird glowing aqua eyes, the pale skin, and the one wing he tends to sport sometimes. However he usually tries to subvert this by wearing glasses (with the glass taken out) and sweaters or polos. He's also as tall as his father.
Gabriel has never even met Sephiroth, probably because he's Sephiroth and Gabriel's origins are strange. He does see Sephiroth as his father but only in a technical term, He wants nothing to do with him at all and he's sure Sephiroth feels the same.
Though whether or not he's one of the many clones of Sephiroth is debatable.
He doesn't really have any friends. He does consider his roommate, Ray, to be his friend. He's still trying to build up the confidence to tell him.
Gabriel doesn't want to have any, since the term "enemies" back in his world usually ends in monologues and a fight that ends up with the bad guy dead. Usually.
He does have a crush on someone, he's just too shy to tell them.
Gabriel is first and last name come from two archangels.
In his bio the note that says Sephiroth's name echoed throughout the building is a reference to TeamFourStar's Final Fantasy Machinabridged. And the series every time his name is said by the characters, a chorus of people chant "Sephiroth!" soon after.
Gabriel is a clone of Sephiroth but he may be an entirely new one or an existing one with scrambled memories or amnesia.