One Piece: I'm Destined to Be the Son-in-Law King! - Chapter 166: The Sky, Cracked Open

In the waves of steam and machinery, who could achieve extraordinary? In the fogs of history and darkness, who was whispering? I woke up from the realm of mysteries and opened my eyes to the world.

Firearms, cannons, battleships, airships, and difference machines. Potions, divination, curses, hanged-man, and sealed artifacts… The lights shone brightly, yet the secrets of the world were never far away. This was a legend of the “Fool”.

- Description from novelupdates

Unluckily engrossed in reading, she traveled back to a time where men were honored and women were belittled, feeling utterly miserable.How could she change the current situation?If the farmer girl is not strong, her family won't tolerate her...

Kazekaze thought he was just an ordinary kid in the world of Naruto.- No Sharingan.- No Byakugan.- No Ōtsutsuki bloodline.Just a normal seven-year-old trying to survive in a ninja-filled world.That was… until his father brought him back to Konoha.And he discovered the terrifying truth:* Senju Hashirama, the God of Shinobi, is his grandfather!* Senju Tobirama, the Creator of Ninjutsu, is his great-uncle!With the blood of legends flowing through his veins, Kazekaze must rise to become a shinobi worthy of his lineage.A Genius Among Monsters—But Can He Surpass Them?

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?