MTL - Players Please Get In the Car - Chapter 14 Sausage

An alien race invaded the Earth on June 6, 2128. At the midst of this war, many nations allied with the alien threat and the war nearly wiped out the rebelling humans of the planet. At the edge of mankind's survival, the United Nations Army launched its forces to eliminate the immediate stellar threats that loomed over Earth.

General Seeker Carlean, commander and leader of the mission, risked and gave his life to destroy the immediate stellar threat. The battle was won though Earth lay in ruins. Perhaps mankind will live to see a few years of peace before the alien threat returns to wipe out their existence.

At the immediate aftermath of the stellar battle, the fallen Seeker Carlean awakens and finds himself at aged 17, living the peaceful life he lived 16 years before he died.

So begins a new game in the battle for humanity's survival.

The dawn era after the end of the half century has gradually rebuilt the order, abandoned civilization, and is full of undivided violence and desire.
The noble and powerful pioneers are in charge of the city, and the evil and mad plagues are in the wilderness.
Pure human beings who cannot mutate are the weakest, dominated by the rulers of the pioneers, and are not as good as animals in the wilderness.
A purely humanized young man with a worldly experience has quietly entered the WTO, holding a three-foot long knife and a long-distance desire to boil in the world of purgatory. From the nameless name to the sorrow of the Supreme Court, the name of the black ride is resounding!

- Description from Uukanshu (translated)

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.