10 nen goshi no HikiNiito o Yamete Gaishutsushitara Jitaku goto Isekai ni Ten'ishiteta - Volume 12, Chapter 7 Yuuji, finally resolving himself in his fifth year of living in another world

This story is set during the end of the Sui Dynasty, a time where multiple powers struggled for supremacy and power.

He returned with a vigorous presence, equipped with a Heaven-reaching Innate Ability. He could heal, tell fortunes, refine medicines, set formations, and refine talismans… “There’s nothing in this world that I can’t do!” — Shen Feng.

After 10,000 years, it was iced. The Douro’s federal expedition team discovered an egg with a gold and silver two-color pattern during the scientific study in the northern part of the country. After exploring it with an instrument, it found that there were vital signs inside, and he quickly brought it back to the institute for incubation. The egg hatched, but it was a baby, a baby identical to humans, and an egg-born child.

- Description from ptwxz

Sen, the last and most powerful dragon left roaming the skies causing chaos and destruction across the land. When all hope is lost the human race call upon their last hope, a powerful witch. Unable to destroy the dragon the witch uses the last of her power to cast a spell. Sen has not been defeated but has now been reborn as a human.