User blog comment:B214/Volume 22 spoilers/@comment-50.139.232.230-20160610182436/@comment-183.88.34.245-20160619073033

I agree about the group of old devils want to hold some control over Issei. In the volume 18, when the first head of bael suggested Issei to become Maou, I saw it as an attempt to leash Issei with chain called "responsibility of Maou". Sirzech also was held with the same chain and need to bend to demand of conservative devils for many times.

Still, the conservatist's action is understandable. unlike Sirzech who was born as a devil thus has a devil's mindset, Issei was originally human and his mindset is growing similar to that of the dragons (do thing as he pleases, albeit with more responsibility for his action). moreover, his power is keep increasing in an insane rate (one year early, Issei was completly normal human. now he is a powerful individal who figth with a lendendary evil dragon Apophis and win). just Imagin that Issei become a second Great Red who can do anything without single care about blood purity or noble privilages. those old devils will never like that.