MTL - Cosmic Professional Gladiator - v2 Chapter 30 unique

High school student Mikoshiba Ryouma was summoned to a different world in the middle of a war. Sensing the malice from the one who summoned him (a summoner of the O’ltormea empire), he uses his martial arts to run away, killing important people of the empire during his escape. After the escape, he rescues two twin sisters from the hands of thieves. The sisters who can use magic, swear to serve him as subordinates. Thus, Ryouma begins his journey on the path of the supreme ruler.

While the demons were rising, mankind was about to become extinct. Six temples rose and protected the last territory of mankind.

A young boy joins the temple as a knight to save his mother. During his journey full of miracles and tricks in the world where temples and demons are antagonistic to each other, will he be able to ascend to the strongest knight and inherit the sealed divine throne?

- Description from novelupdates

Eren Idril died as an old, decrepit, and piss-poor adventurer by the maws of a D-Rank monster. He had a lot of unfulfilled dreams and desires that couldn't see the light of the day after the light in his own eyes died down.

But fortunately for him and unfortunately for the world, that wasn't his end. Eren was somehow dived back in time when he was a mere teen, attending Lionheart Academy for adventurers.

When life gives him a second chance, Eren decides to exploit it to its fullest. Experience his vile deeds as he partakes in them without feeling the slightest bit of hesitation.