I can suggest two fanfic I am writing.
One is about MHA and is called TRIALS: PATH TOWARD GODHOOD(+100 chapters and still ongoing.) The cover picture is Himiko.
The second one is new one about DxD is called MIRACLE CHILD: SLASH THE GODS (just 5 chapters for the time being but I post daily.) The cover picture is Rosweiss. Though, it might change.
The novel you're searching for is called: God of slaughter.
Regius_Sanguis all the reviews count. It's not like the power stone
Frankly, everything is relative. You have the right to write a review the author has the right to delete them.
I read a story about a hero who was betrayed by all his friends. He went back in time before the time he was summoned swearing revenge. The revenge part didn't begin before more than 200 chapters since the first hundreds of chapters he was still on earth with his family. That didn't really bother me since I liked what the author was writing. So it's a question of taste and perspective.
For example, in most CN the synopsis says that the mc will become a god. But generally, he won't become one before the very end of the story.
Of course, an author should be ready to accept bad reviews. I received a 2.5-star review once, but it didn't bother me. But 1 star is too much. 1 star means that everything the author did is shit. Just so you know there is stability update in the rating. So imagine a bad writer who still posts at regular times. How could he accept having 1 star since it would mean that even his release rate was given 1 star?
Anyway I understand your frustration, but try to understand the authors
Regius_Sanguis he needs ten reviews in order to be rated
MisterImmortal OK. I will read and give a review Take a look to mine also.
Regius_Sanguis ok. You can take a look right now to my story. I have only four chapters posted.
Also I really like the three you used for your cross over. I will go take a look right now
kazesenken yep
Give me a honest review. I don't mind harsh review as long as the make me better. I will wait 
Do you still need review? If so here mine:
https://m.webnovel.com/book/15439230705411305
The first one is a fanfic cross over with MHA as the first world.
https://m.webnovel.com/book/14979532805339005
The second one is an original story.
It's the first one who needs the review, but I won't mind getting more reviews for te seconds one
The_Canary OK. It's already 1 am here let me take a look after I wake up and I will write a review for you. Don't forget mine.
https://m.webnovel.com/book/15439230705411305
It's a fanfic with multiple cross over. The first world is My hero academia.
Aysel_Inara hello. Sorry I just saw your reply. OK come read mine and give me your review . I will read your right now
A story about myth. It's called ENDLESS MYTH:Surpassing the Gods
I forgot. It's a fanfinc. The first world is My hero academia
I just posted the first chapter of a new story I'm writing. Come and take a look. It's called THE TRIALS : PATH TOWARD GODHOOD.
https://m.webnovel.com/book/15200291505382805
https://m.webnovel.com/book/14979532805339005/41025167740164681?from=detail&
It's story about myth. Mainly Japanese, Chinese, Greek and Nordic myth. The mc is a member of a family of constellationist(people who gain power from different constellation)
https://m.webnovel.com/book/14979532805339005/41025167740164681?from=detail&
Try this. It's a story about myth