I understand the frustration but we also need to under alll of that happen in such a short time that it's make more sense that the most impactful help(attack) take the spotlight. For the Amy Kirio, none of the demon there know bout his ability, since he's a nobody to those demon. But the complain and frustrating feeling is VERY valid ლ(´ڡ`ლ)
And he wasn't even supposed to be able to save the princess without their help（￣へ￣）
I don't think so, as we can see iruma attack does nothing on the glutton since AMY put barrier so that the guy ( i forgot his name ) can be the HERO#－.－)
Kinda spoiler
It's annoying to see how a place with some of the highest ranking demons didn't notice Iruma and Azz-kun immediate response when that Princess Ashura was about to be attacked. What's worse is no one noticed that Amy Kirio when his barrier is BIG and blocked Iruma. And the worst is he walked away as if nothing happened when he's a KNOWN criminal already. Anyways, that's my only complaint