MTL - Apocalyptic Return To Famine - Chapter 446 misfortune

In a world where human and monsters relied on mystical fruits and their inner power to fight for dominance, a lost soul was thrown, given the powers from all the other worlds he’s known. But there was a catch; he had no control over what power he would get! With knowledge beyond that of most, he sails his path to the top of the one piece world!

- Description from Novelupdates

Lin Qi transmigrates to a world of immortals. In this world, there are sword immortals who can behead a person from a thousand miles away, peerless great demons who burn mountains and boil the seas, and ancient gods and devils who can divine the heavenly secrets.

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