The Villainess Enjoys Her Seventh Life as a Free-Spirited Bride (hostage) in a Former Enemy Country - Chapter 111.3

Qin Fen had once been abandoned and broken until, one day, he picked up a liquid metal ball that turned his life upside down.
This is the interplanetary era where Classical and Modern Wushu are competing. Classical Wushu enables followers to grow as powerful as dragons and elephants, whereas Modern Wushu enables followers to freeze monsters or even extinguish erupting volcanoes.
Qin Fen steps onto the stage of both Classical and Modern Wushu while belonging to neither. With the exquisite combination of both Classical Wushu and modern technology, he will pave a way to become a legend.
He is one of a kind, a favored son of heaven.

Zheng Tan somehow returns to the year 2003, turning into a black cat. Picked up from a rubbish heap by the Jiao family, he is given the name “Charcoal”, and so begins the life inside Professor Jiao’s family. Zheng Tan remembers that he was once a person, but currently his body is that of a cat. He has no way of speaking the human language, but can understand it, and even retains the thinking and IQ of a young 20 year old youth. Read along as he adapts to this new world, and somehow tumbles from a group brawl to catching a thief.

- Description from Novelupdates

Jade Hunter? The man which many women want to meet? If she really was a girl, then if she were to dress in a female attire… wouldn’t she look beautiful and refine? She is his fiancee? Could it be that she disguised herself as a man to avoid marriage? She would rather go catch thieves and hunt for bandits than to marry this wangye?

No, he will not let this happen! She is bound to be his!

For the arrest of a bandit, she became the hostage and jumped off a cliff? Dead?

…Nonsense! He does not believe! She is destined to become his wife, and he will find her…

Found her!

Although she repeatedly denied and repeatedly avoided him, he will find a way to let her fall in love with him!

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?