"I don't know if I have the capability of being kind." He can behave himself and he can be as good as possible. But kindness is foreign to him.

"I was..I've already seen you leave once. I figure it could happen again at any time." Or he might be the one to leave the platform and never have the chance to tell xingchen how he felt ever again. He would simply be going back to nothingness and his death.