Karia appears first in book six, Sweet Revenge, of the Black Tree series. This is a guy you never want to encounter. He was created for the sole purpose of destroying entire worlds. He is the universe’s only tenth stage virus, which means that he can infect anyone and anything. It’s only a matter of rearranging himself into the most effective form to pass from one person or being to the next. He can destroy a world in a matter of weeks, which makes him the most fearsome virus to have ever existed. Currently, he takes on the humanoid form of a Jupiter vampire, with dark red hair and dark green eyes. Sometimes he is known to take the form of a snake, perhaps linking him to the god of gods, Mardock. He can usually be seen sporting leather. Mark Blue’s family absolutely hate this guy, and with good reason. Their own planet was nearly wiped out by him hundreds of years prior to the events in the BTS. It is for this reason that “Professional Griefers” by Deadmau5 and Gerard Way seems to fit him.