Days as a Spiritual Mentor in American Comics - Chapter 112: Black Robe Inspection Team Spin-off · Prologue_7

With the Goddess’ blessing, he became a 『Divine Knight』 and founded an Empire.
As time passed, he grows older, and by the time the heavens called for him to come, the Goddess showed before him, asking for his last wish.

He wished to be reincarnated in the future.
He dedicated all his life for his people, he had no time to master his own arts.
This time, he wishes to live for himself, forging his body to the utmost limit.

The Goddess complied with his wish.
In the far future, the King shall reincarnate as the 『daughter』 of a renowned Knight family.
And, under some circumstances, she is labeled as a failure of a Knight, however——

「How convenient. I can stand on the foremost line without needing any rank. No better training than actual combat!」

Thus, the legend of the world’s strongest, most beautiful Knight Disciple (♀) has begun—

The female protagonist crossed over to become the Venerable Woman Kingdom’s Crown Princess. That’s right, that’s right, holding power and authority and handsome men!

What? She’s has the body constitution of trash and is unable to practice martial arts?

Having finally set her eyes on a good looking man, he turned out to be a snow wolf. Isn’t that just so sad and depressing….. Having captured a good looking man, a certain woman laughed sinisterly. “Remember this. You are already mine, so you have to remain chaste for me. If you do not obey, I will then reject the goods.”

The handsome looking man was stunned with his mouth agape. “You….. You’ve gotten it completely backwards!”

- 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?

- Description from novelbuddy