Umm, how is this possible? Seriously. Billie must have like super strong telomeres or something that don't ever let his chromosomes deteriorate. Basically, that means there is no degradation of genetic information and he doesn't age (or just EXTREMELY slowly).
Of course I'm joking here, but dear god, he is really amazing. Whatever is going on in him is sure working. That's almost 10 fucking years and he looks just barely any older!
Clones by the dozen...?