Reincarnated With A Glitched System: Why Is My MP Not Running Out? - Chapter 21

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

Before he was a little over 10 years old, he was the nightmare of the Gorge of Heroes and the headache of countless people that had been abandoned by the world.

After leaving the Gorge of Heroes, he became a legendary figure of the number one academy in the continent, and he alone brought numerous changes to it.

Thereafter he stepped foot onto the continent to become a legend, but the road to become a legend was far more difficult than he’d imagined….

On a continent where puppet masters reign supreme, using anything and everything as weapons: living creatures, shoes, daggers, pendants, clothes, shields, guns — which they call puppets, this is the story of Bai Xiaofei with his trusty sidekick, Huskie, on a quest to find out exactly what happened to his parents and become the greatest illusion stream puppet master the world has ever seen. This is a story of wit, plot twists, love, strategy, cultivation, humor, and the unknown.

Feng Lingxi was the traditional family’s head mistress – a person with a charismatic yet sly personality with the ability to attract people easily to her side, and having the potential to take someone’s soul away. Crossing across boundaries from a decade ago to now, a world that gives woman full respect and acknowledgement….

Don’t be fooled by her, because she was someone who would act obediently in front of a crowd but, stabs them in the back when necessary! Disguising as someone that would gain her trust and belief! That was why the Emperor of Xian started doting on her, allowing her to become absurdly daring to do whatever she liked. This made the Empress speechless to tears.
That would be the cause of the kingdom’s downfall in the near future…

- Description from Novelupdates

…but it seems pretty doable.