Hmm... How best to describe him.
I'd say... assuming you wish me to describe his personality, that he is someone who is simply having fun. Yes he may be fighting horrible monsters, and perhaps even the world is on the line, but what's the point if it isn't enjoyable?
The life of others however is just as important as his own, and if he could give his life to save others than he'll gladly do it with a smile on his face and a witty and/or humorous remark coming from his mouth.

Will that suffice? Or should I write more? Or did I understand wrong?