Isekai Maou to Shoukan Shoujo Dorei Majutsu - Volume 7 Chapter 4 part2-3

The world is in ruins. Extreme sub-zero temperatures suffocate the surface, making even simple survival an ordeal. Frozen derelicts of bygone eras span across massive ice wastes. And the survivors closely guard any technology rediscovered within.The only escape from the deadly climate is beneath the surface. But it’s another disaster underground. Monstrous machines lurk in the depths. Unhinged demigods war against them, dying over and over, treating it all like a game. The land itself shifts over time, more contraption than rock. And an ominous prophecy states that the key to everything waits on four heroes - but nobody knows who or where they are.When an expedition into the far uncharted north goes terribly wrong, Keith Winterscar and his father get trapped together in a desperate fight for survival. Stumbling upon an ancient war of titanic scale; the two will need to set their differences aside while they struggle against Gods, legends, and the grand secrets of the realm that lies below.

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

What if your own father and his mistress were behind your mother’s death? What if you were about to be sold if to a scumbag?