First of all: Don't be fooled by the chapter-count.
If we consider the average length of a chapter on this platform, then this marvellous piece of fiction settles somewhere between 100 and 150 chapters at the point of this review.
Writing Quality: The amount of mistakes is negligible and most of those are typos.
Phrasing, dialogue and scene setting are superbly well done.
Story Development: After an interesting prologue, the main character has a rather unique start into the world of DxD.
He starts way before canon and the author does not rush. His pacing is well done and the time skips are reasonable with a well written recap of important happenings.
If you want to know more, you should read the story, as I don't want to spoil anything.
Character Design: The MC is a tad manipulative, but it never takes over the story to the point where we see schemes within schemes and plots within plots.
Instead, he uses refreshing honesty where necessary, having mastered the ability to manipulate with well set kernels of truth.
He is also well versed with lies and deception, as well as brute force, should it be necessary.
He is rather intelligent, which actually shows in his actions, rather than just in the authors praise.
Secondary main characters (as calling them supporting cast or even side characters would be rather insulting) is where the author really shines.
He takes the time to flesh them out and give them personalities, that actually develop in a believable way.
Sometimes, when there is a timeskip, that spans over a longer period of time, he'll skim over the development.
They do act in a way fitting their characters, though, and we get small details over the course of the story, that explain the quirks and characteristics we see in them.
This makes them relatable and fun to read.
There wasn't a single PoV, that I truly disliked yet in this story.
Updating Stability: Well, it's very nearly enough to sate my appetite for... nope, can't lie to you.
It won't ever be enough. But his updates are rather stable and the chapter length is fantastic.
World Background: He uses the DxD-verse as a template and borrows from other franchises in a playful and very integrative way.
Nothing, that he writes into his story seems out of place, everything fits.
The way he does that is honestly a bit admirable.
Overall: This is the second time I've given a genuine 5-star review, I think?
I'm rather picky in what to review, and most of the stories, that manage to impress me enough to post one have a little thing, that's a bit lacking.
Not this one, though.
Please try to get i to it, I'm rather sure you won't regret it!