User blog comment:B214/Volume 23 discussion blog/@comment-139.190.27.252-20170323120038/@comment-30048084-20170323181844

@Bennia Lover Sirzechs isn't going to be happy about that his son already loves Oppai Dragon imagine how he would feel if Issei also makes up his own team of heroes though if he tried anything chances are Grayfia would kill him if she doesn't kill him after the stunt he pulled with Trihexa.

also you forgot Asia the Gold Panty Ranger name courtesy of Fafnir

If Issei completes DxD G mode it would literally mean that Issei would become infinite then he can't use DxD G anymore unless it is against beings like Crom and Vali.