I've always liked him. Traumatized as a child, losing everyone who mattered to him. Felt alone, and built a wall around himself because he is legit afraid to connect to anyone because he doesnt want the pain of losing anyone again. Gets trained as a child soldier, where that mentality is encouraged in him to make him a leader.
He doesnt know how to react to everyone trying to befriend him, and closes off even more. Throughout the game, you see his wall cracking as he starts letting slip his concern for his allies, even if just in his personal thoughts; but its even shown physically when he starts hesitating or getting distracted by his concerns for them when he is unaware of their status; this is even picked up in by his allies at the time.
And finally it all comes crashing down around him with the situation with Rinoa, where the thought of losing her shatters his defenses and he breaks down, showing his fear of losing someone again.
I would love an updated version of the game that showcased more of everything, but even the default game didnt hide what kind of character he was if you looked 5 minutes past the "Cool, uncaring edgelord" facade he put on.
http://tinyurl.com/b95dwtg