Markus Quint
20 years old
6'2"
Brown Hair;Brown Eyes
The group of friends he will have come down with is his Bujinkan martial arts group. As a result, he will be lean and strong (but not like a weightlifter strong), quick, and knowledgeable in self-defence. This way, we have someone that can do something should things get in close. This will compliment is full-immunity, for the time being. While you are emotionally fragile, his martial art teaches him to remain calm, cool, and able to think things through. While he might not be as much of a problem-solver, he has basic tactics for fighting, and because of his calmer nature, he can help to follow the plan laid-out by your character before hand, and be available for any ad-libbing in between.
I think the "my char being more important to save" should be something that is moreso unknown than it is known. So they are both trying to survive, and he doesn't know that he is immune, till later.