Koko wa Ore ni Makasete Saki ni Ike to Itte kara 10 Nen ga Tattara Densetsu ni Natteita - Chapter 31 - How to Protect the Lord God Fowl

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—

Xuanyuan was reborn into a strange new world where training to be a Xian was a cornerstone. There was however something ancient dwelling inside his body. He could now devour all of creation…

“Dear, it's time for your medicine!”The beautiful and pure Holy Daughter brought over the medicine for treating his wounds.On this day, he saw betrayal with his own eyes and experienced despair with his soul...From this day forth, the Hero was dead, send paper offerings if you must!

After reincarnating as Zhou Xuanji, the prince of an empire, he thought that he would be able to live a worry-free life of luxury. He did not expect to be involved in a rivalry with the Empress herself, who forced him to escape from the palace.