Toaru Majutsu no Index SS - Volume 2, Chapter 11: Every Field has Exceptions. The Second Friday of July.

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

I finally managed to kill the demon lord.

Every time he dies, Ethan Hill gains a little more power.Earth was chosen for Integration, but Ethan knows from the second his Trial begins that the Integration is a lie. These creatures giving Earth the 'honor' of access to their Interface want something from Earth - he just doesn't know what.Now he's trapped on an alien planet and lost in a time loop, fighting for strength and for his own humanity.One thing's for sure: He'll die as many times as it takes to tear it all down.

One day, Raizou ​​Takakura, an average salaryman, had a Heart Attack and his life ended that day.

But, he got a second life, in a different world.

Reincarnated with strong skills―― wasn’t what happened to him, instead, he was reincarnated as a foot soldier in a small country, Highserk Empire, which was surrounded by large countries.

With a new name, Walm, he was thrown into the frontline of war.

Covered in blood and the stench of death, along with his comrades, he was slipping through life-or-death situations.

An adventurer party with members that could use powerful magic, transferees with overwhelming power called the “heroes”.

In a deadly battle with them, Walm gradually developed his talent as a warrior which would’ve never awakened if he were to stay in times of peace.

While his eyes becoming dark and muddy over time――