Its hard to pick just one. Probably a mix of Cassie/Tobias/Marco. I like animals, and helping people who aren't jerks, but like Marco when people's lives are really on the line I'd always take the pragmatic approach to protect them, even if it ended up with me feeling guilty. As for Tobias, if I had the chance to escape my family at that age with morphing power, I definitely would have done it and just hung out in the woods with the cool aliens until the war was over and I was old enough to live on my own. Though I don't think I would have become a nothlit, I like keeping my options open.