I regressed and became the Sword Ice King - Chapter 393- Festival 124- Raid on a Rainy Night 63

The first great emperor in the world was betrayed by his confidante and perished. Millions of years later, the great emperor’s soul returned and was reborn as Ye Yan, the son-in-law who was kicked out by the Chu family with a letter of divorce, restarting the supreme journey. Open the gate of immortality, kill the Jiuzhongtian, and cast an invincible name again!

- Description from novelbuddy

In the 5th year of Konoha’s founding.The battle between Hashirama Senju and Madara Uchiha at the Valley of the End had come to a close.In order to treat his elder brother’s injuries, Tobirama Senju resurrected a medical ninja from ancient times, hoping that this individual could prevent the injuries from shortening his brother’s lifespan.This medical ninja’s name was Emiya Shigen.

Earth is dying. The sun is expanding at an uncontrollable rate, but Theo Spencer is alright with this. He's led a deplorable life. When the end comes, a mysterious entity grants him the gift of reincarnation. The gift of a quiet life as an alchemist.

Theo awakens in a small town in the southern reaches of a small kingdom in a non-human body. Broken Tusk doesn't seem like much, but his legendary alchemy skills will soon turn their fortune.

Join Theo on his journey to turn the swamp-town of Broken Tusk into a prosperous trade town.

In childhood, they were neighbors. Xie Zhen always bullied Li Yu.