The Daily Life of the Demon King - Chapter 325: The Priest’s Invitation to Tea and the Death of Another Cockroach"

In regards to the MMORPG Cross Reverie, Sakamoto Takuma boasted an overwhelming strength that was enough for him to be called the Demon King by the other players. One day, he gets summoned to another world with his appearance in the game. There, there are two people that insist “I am the real summon master.” Takuma gets slave-turning magic used for summoned beasts cast on him by the girls –

The universe gave me another chance after life screwed me over. My second life brought me to a world where people breath fire, walk on water and some people with special eyes that give them bullsh#t powers. Well, I got the gamer ability. And I’m gonna use it to stand at the peak. But it's gonna be a long journey before I reach that summit. SI - MC.

They love gold, and they love silver. Even more so, they love gems that dazzle, like stars across the skies.
Firearms, jewelleries, and precious metals; A collector’s world will not be complete without antiques.
Storage auctions, old goods trade, re-estate sales and gold-digging. But the truth is, if one wants to make money, then the supreme way is through searching for the legendary treasures.
Holding the fort, there’s an ocelot, a wolf, and an Andes condor. At the side, there’s a loyal hound, an irascible ape, and an African honey badger. Who said that you can only rely on humans when treasure hunting?!

- Description from Novelupdates

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?