User blog comment:Crimson and Darkness/Volume 25 discussion blog/@comment-77.182.125.30-20180521144211/@comment-29963364-20180527042128

1.) [Outrage] might be the Dragon's equivalent to [Hysterical Strength]. It's the phenomena that humans display during moments of extreme emotion/stress (like a mother lifting a car off her child). It's more of a "triggered state" rather than one that can be entered (like [Super Saiyan] from "Dragon Ball Z").

And considering that Fafnir activated [Outrage] after seeing Asia get hurt, and how protective he is of her, this is most likely the case.

2.) I think "Divinity" might be tied to whether or not a being is "considered a God."

By this, I mean "is there a religion (in the DxD Universe) that recognizes him/her as a god/goddess?"

The Heavenly Dragons are God-class, but aren't gods, because they aren't deities in any existing religion.

"[T]he fraction of Balor that had lost its divinity" might be a reference to the fact that in Celtic/Irish Myth and Religion, Balor was killed. So Balor losing his "divinity" may be because he's "no longer a god" as far as the world is concerned.

Even Ophis, despite very clearly being a Dragon, is "considered a god" because there are many existing cults and belief systems that portray/worship the Ouroboros (Ophis' symbol).

Issei might be gaining "divinity" (as Chichigami says) because Oppai Dragon is becoming a symbol of hope & peace and many all over the world. This, combined with his soul practically be saturated in Ophis' "divine" power (at least slowly, since he's awakening it), could be what eventually turns Issei into the one and only Oppai Dragon Devil God Emperor.