My Necromancer Wife - Chapter 59: Host.

As a promise, he went out into the world as an assassin. 3 years later, after becoming the Supreme Assassin, he gave up on everything he had and returned to the ranks of ordinary people. But one day, Kismet, a mystical game created by the National Research and Development had appeared.

Enigmatic hands, spectral frame, and one cunning strike just like the swing of the Grim Reaper. The Supreme Assassin takes on the mystical world, and how his legendary tales sets off, progressively ascending the altar to becoming the best.

- Description from Novelupdates

Monica Everett, a genius magician, was extremely shy and terrible at speaking in public.

To that end, she worked hard and mastered the art of countless magic, which she could use without chanting. After being chosen as one of the Seven Sage at the tender age of fifteen as the “Silent Witch,” she lived a quiet life in the forest.

However, two years have passed since then, and one day, Monica received an order.

And it was to secretly protect the second prince to the academy undetected.

In order to protect the prince, Monica must infiltrate a glamorous school for the children of noble families.

“I don’t wanna do this… I’m scared… Ugh… My stomach is aching…”

…said the girl whimpering.

God plucked one of his creations from his first Earth and gave him a second chance in another one of his Earths...surprise it is in DxD! Now reincarnated as a perverted side character how will our poor protagonist handle his new identity? Well he probably wont make the choices you will want him to, that's for sure!

Three thousand years ago, gods and Buddhas disappeared all over the sky, and the inheritance of practice was broken. It was not until the ancient civilization was destroyed that spiritual energy recovered. Ten thousand races took advantage of this to invade.

Five hundred years later, the human race gradually rose up and began to fight for control of the land of China, and counterattacked all races.

Three hundred years later, Fang Yi, the Lord of the Great Dao, slaughtered all clans, destroyed all the heavens, stepped out of the myriad realms, and fought against the Dao of Heaven.

In desperation, Fang Yi sacrificed blood to eight hundred small worlds, reversed time and space, and was reborn nineteen years old.

In this life, he wants to live a more relaxed life, perfect his Dao Xin, and conquer the Dao of Heaven again.

- Description from novelbuddy