DxD: Matsuda? - Chapter 99: Sona Sitri vs Rias Gremory?

In a post-apocalyptic fantasy world layered into multiple realms, humanity faces extinction due to their endangerment of the main realm. Forced to merge all realms back into one, a deity grants humans a leveling system to empower them, lest they become extinct when facing the mythical creatures. Noah, our protagonist, embraces the role of a monster tamer, trading his humanity for strength and eventually transforming into a monster himself. As Noah struggles with his evolving identity, he must navigate a world where the line between human and monster becomes increasingly blurred.

Violet skies, a world undergoing massive changes, a deficient moon, interlinking voids…
When the world experienced a cataclysmic event,the majority of living things ceased to exist. Although humanity survived by hiding in the last safe zones, humans had to face mutated dire beasts and colossal source beasts that could break through the space barrier and enter the earth at any second.
Luo Yunyang, a young man who grew up in those calamitous times, obtained an attribute regulator and set out to walk the path of supremacy!

- Description from novelupdates

The Soaring Dragon Continent is a world of summons, you can only become strong if you become a summoner! Yue Yang, an average high school boy, was suddenly transported into this world. When he woke up, he was greeted with a lot of worried faces and found out that he had assumed another person’s identity. Turns out he’s the good-for-nothing third son of the Yue Family, who had just recently drowned himself because of a failed engagement. Unlike the third son of the Yue Family who was useless in summoning, Yue Yang succeeded in making a contract with a summoning grimoire on his first try, even when the other guy failed for the past fifteen years. Others would have a headache making contracts with beasts afterwards, but countless beasts tried to gain favour with Yue Yang instead, acting like a good kid before him.

Yue Yang the brat, however, didn’t feel grateful at all: “Scram, Mythical Beasts! Do you think you are cool like that? Go away from me now, I only like beautiful summons!”

Even when royal families approached him for his talents, the shameless brat replied, “I’m not interested in government stuff, I’m only interested in beauties!”

- Description from novelupdates

I reincarnated with e*otic game skills, but this is apparently an apocalyptic dark fantasy. I can’t die, so I tried to save the world with e*otic game skills… “Saint! Save us!!” “Saint! Save us!!!” People keep calling me a saint.