So, the Master has a great plan of changing humanity. Then a VD guy comes and tells him that mutants are sterile and the Master kills himself. Could he have done something different? IMO the solution is hidden in the name of his human followers - Children of The Cathedral. I wonder why he didn't simply start farming his followers? He could have decreed that before they can be changed into mutants they have to have x children. Also, he seems to need human scientists anyway.