Going to finish reading vol6 tonight (I feel as if I am rushing through the novels - going to suck having to wait for the next book T_T), I think one key element here is that Raishin may "not" be the prophecy child. It may be his brother, or it might even be someone else.
It has been pointed out that the creation of human (or even something infinitely close to a human) is an act of a god. The knowledge to do so can be catastrophic and desired by many. What if, say, someone else is the child of prophecy and, at the end, Raishin has to defeat that person to prevent world domination?