10 nen goshi no HikiNiito o Yamete Gaishutsushitara Jitaku goto Isekai ni Ten'ishiteta - Chapter 9, Part 13: Yuuji, cleaning up afterwards with the adventurers

The notorious imperial court lackey and the meritorious military general were well-known for their mutual dislike, a pair of arch-enemies set in stone. Who could have foreseen the unexpected change in the winds of heaven: the general injured on the battlefield, both legs disabled, and even forced by the emperor to marry his nemesis.  

With one marriage edict, two people with mutual hostility are forced to marry and live under the same roof. Yet after these long days together, they come to the realization that this fellow is not truly devoid of any saving grace/unattainable and high out of reach.

- Description from Novelupdates

This is an alternate history. Decades after the fall of the Eastern Jin Dynasty, the world is still in chaos, although there is hope for reunification.

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.

Rakna was not normal. No, unmistakably not.

Whether it was his appearance, his personality, his abilities, his identity, nothing about him had ever been banal. Was it his choice?

No. He was merely but a tormented soul doing its utmost to live the life it had learned to never enjoy.

Would being picked by a glorified universal abductor calling itself a system bring something out of him?

Would he finally learn to breathe in the pool of blood that suffocated him? The Harvester does not sow, he only collects.

All he has ever known to feel was loss and the only thing he can do is take.

He will devour their hearts and drink their blood if it is what it takes.