In chapter 4, Sirene has combined with a Mechasaurus demon and is heading for the lab. So Devilman and Getter Robo combine into Devil Getter and it looks sick!! The Lab puts up a Magnetic Barrier but Devil Getter f's up Mechasaurus Demon Sirene's monsters with a big a55 axe!! Sirene blasts through her own guy to nail Devil Getter but he gets up and nukes her with a Getter beam!! but it melts her and she turns into Mecha Demon Sirene!! as Sirene and the mecha parts survive and her strength survived (like in Contra when the boss has another form). She blasts em but they undo their fusion and Devilman grabs Sirene's breasts. He tells her that she should be sexy and that her fused form wasn't. Pulling her out of the Mechasaurus fusion, Getter Robo beats the machine she was fused to and Sirene thanks her for making her remember Amon. She kicks him away and tells him that she will kill him next time.