Toaru Majutsu no Index - Volume 13, Chapter 8: God’s Right Seat and the Imaginary Number School District. Fuse=KAZAKIRI.

Long Fei, a cross-timer and doujin, is an otaku who traveled to another world. In the original world, he was an otaku fan of Gundam and military science fiction.

He died in an accident and was reincarnated into another world. The Gundam works he had read before his death and the techniques in various military novels could be brought to another world.

How would he use the Gundam that Long Fei created? What waves can be caused in this different world?

- Description from novelbuddy

The real daughter of the Lin family, Lin Luqiu, was lost for many years and was found suddenly, only to be asked by her parents to replace her fake daughter sister in marrying a living corpse!She uses her exceptional medical skills to wake her vegetative husband, but to her surprise, the first thing he says upon waking is, “Let's get a divorce.”She laughs in anger, “Fu Jingchen, you really are an ungrateful dog of a man.”After the divorce, everyone learns that the seemingly rustic girl is actually wearing many hats as the true powerhouse.She is actually the prized disciple of a giant in the medical field, a world-class piano master, and a genius jewelry designer... all of these are her.Later, a regretful President Fu comes to ask her to remarry.She dominantly refuses, “President Fu, sorry, no time!”The man pulls her into his arms frantically, “As long as you come back, I will give you my life!”

“Welcome to the Cosmos of Madness!”

Said a man with long red hair and piercing golden eyes as he descended from the stars.

“You have been chosen for a great purpose! Task! Mission! Destiny!”

He shouted dramatically as countless worlds heard his every word, from the lowest peasants to the mighty entities in the lofty palaces in the Higher Dimension.

“All of you accept your destiny as a sacrifice to Daemon Sultan, Blind Idiot God, Primordial Demiurge, Azathoth!”

And then Apocalypse descended.

***

Follow the journey of self-named Samiel Zentaur, a half-mad worshipper of the Outer Gods, on the Path of Transcendence and in his path to find himself.

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