Rebirth of Billionaire's Wife - Chapter 20: Allow me to clarify

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

A streamer who died during his gaming stream gets transmigrated to a game he died on. With his second chance to live, he will survive at all cost to cherish the chance given to him. The Class he chose? The Archer.[ Hello! This is BrightestShinyStar, also known as Sirius. Welcome to my first novel posted in WebNovel! I hope you enjoy reading! ]

The six prefectures of Zhongbo were offered to foreign enemies on a silver platter, and Shen Zechuan was taken into custody in the capital, reduced to a drowning dog—loathed and condemned by all.Xiao Chiye followed the scent of the furor and made his way over. But instead of setting others on him, he kicked Shen Zechuan with his very own leg, rendering the latter an invalid. Who would expect this invalid to turn around and bite him in a counterattack until he was all drenched in blood?That was the start of an epic feud between both men who tore at each other every time they come face-to-face with one another.“Fate wants to bind me here for life, but this is not the path I choose. The yellow dust submerged my brothers deep under. I have no wish to bow in submission to an illusory fate. The imperial edict can’t save my troops, and the imperial court can’t fill the stomachs of my mounts. I’m no longer willing to lay down my life for this purpose. I want to surmount that mountain. I am going to fight for myself.”Note: A ‘drowning dog’ is someone who is down and out, having lost favor or power.

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