MTL - Ace Evolution - v3 Chapter 13

The most feared Assassin in the world died because of vengeance.

Before going to college, an ordinary high school student went to celebrate and got drunk. When he woke up, he found himself in a completely different world. There was a big sect, the approaching sect entrance examination, a slum where his body’s previous owner lived, and a shared memory about a missing young girl.

When he got tangled in a fight with a few punks in this different world, he fell off a cliff and miraculously found himself still alive, with two more voices ringing inside his head. They were Sword Master and Saber Master. In the company of them, he continued to find out more about this whole new world. He took the sect entrance examination, entered the sect, met a strange man in black, and even participated in a major competition of the sect to have a chance to win over his peers!
In this whole new world, he was born again and got to explore the fantastic martial world!

- Description from Novelupdates

Felix Ariel, a typical Floridian, found himself transported to a mysterious kingdom in another world. However, a misunderstanding led to Felix accidentally killing the king, resulting in his untimely demise.Following this tragic event, Felix's spirit encountered a mysterious being who identified as Felix's ancestor. This entity claimed that Felix had been cursed by an unknown individual. For Felix's safety, the ancestor bestowed upon him a system for self-defense.Upon returning to Earth, Felix realized that he would be transmigrated to the alternate world at noon due to the lingering curse. To prepare for this unexpected transmigration, Felix relied on the system, which required him to gather oil and gold to enhance his abilities.Thus began Felix's quest in the other world. With his system, he brought firearms and an ambition to spread liberty... for prosperity and freedom.

“Are you my knight?” The silver-haired youth looked at the blonde girl before him and asked, his cheeks flushed red. This was their first encounter when he was only ten years of age.

“Are you my bride?” He held her in his arms, embraced the girl who had accompanied him for ten years straight. He was sixteen years of age.

“Are you my king?” He knelt before the throne, smiling foolishly as he looked at the girl holding the sword victoriously. At this moment, he looked like the boy he was when they first met.

“I’m fine without having eyes for you. The entirety of Camelot is for your taking.” Smiling soft and gently, he gave his eyes to the girl who lost her eyes due to the curse of the red dragon. He doesn’t regret it, he thinks. He was twenty years of age.

“So… Arthur… Artoria Pendragon, are you willing… are you willing to spend the rest of your life with me?” His voice was soft and clear as he reached out to touch her hand.

This was their legend.

- Description from Novelupdates