Battle Angel Alita: Last Order Omnibus 4

With the help of Porta Nova, Alita''s finally made it to the Incubator, and is moments away from retrieving Lou''s brain, when Super Nova, a new, sinister incarnation of the professor created by Mbadi, steps in and holds all 20,000 brains in the Incubator hostage! Can Alita find a way out? Will Melchizadek be destroyed? And just how many Novas are there?