Kris didn't hold a lot of expectations. But out of all the people he encountered in his life, a stranger, a girl he barely remembered saving, came to his aid and offered him help. She even had the audacity to call him a hero, which further backed up his reasons for calling her crazy!
When Kris first decided to tag along with Dawn, he didn't see himself staying around her long, but then the idiot almost got killed fighting a Griffin, and something glued him to her side ever since then. Maybe it was the sense of protection and a voice of reason, which Dawn badly needed! One key thing that Kris recently noted about Dawn was that she was sensitive to failure and the thought of others leaving her.
"Shit! I can't die here and leave that crybaby by herself. Who knows what would happen if I left her to those two psychopaths!" Dawn's smiling face encouraged Kris to get back up.