@AMONY420 I wanted to send a PM, but I just realised they removed that feature. Anyway, I will give you my review now.
First of all, your description. Recommending readers to not read the book is not good. Second, Gojo himself. He is the only person from JJK in your story and he is not similar to his original character. So people won't be able to relate to him. You can also say that my version of Issei is anything except Issei but there are other characters in the story to make it "DxD".
Third, lack of Characters. There are only 5 characters so far in your book. Gojo, Azazel, Koneko, Rias, and Riser.
Fourth, I saw was lack of Grammar and punctuation. Grammarly can help you to an extent but you need something else.
That is, fifth, familiarising yourself with more literary works. You can read fanfictions of good authors like Dat-Boi-Eraser but reading a lot of books will help you familiarise yourself with story structuring, character development and all that.
Additionally, I don't prefer fast-paced stories so that is a bit minus points for me.
Don't be discouraged by all this. Overall, you lack experience. Even in my case, I have written 3 stories other than the one published here. I just never published those three because I didn't have a 'north star'. Basically I didn't know where I was going. I'm sorry for sounding like a critique but I don't want you stop writing because of any reasons I mentioned.