I Became The Mafia Boss Inside The Novel - Chapter 9: Three Rules

Step into a world where science meets the unknown, where mechas clash in brutal duels, and where every Biocore holds a mystery waiting to be unraveled.Follow Nioh, a genius weapons designer, as he uncovers lost technology, battles biomechanical titans, and pushes the limits of power, in an intergalactic thrilling adventure

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.

There exists eight hardships of human life- living, aging, being sick, dying, resenting, parting with loved ones, being unable to let go, and being unable obtain something.

In each life, each person will experience their own hardship. Once they obtain happiness, they are furthermore unable to let go. Whether it would be heartfelt love or resenting someone down to the bone, would it matter? As long as that person’s bone has my name, it would be good.

- Description from Novelupdates

The Swordmaster who has returned by chance to save the world!