One Piece: My Crew is from Other World - Chapter 4: Being Rewarded

Noah was a social outcast, bullied and shunned by his peers. He suffered humiliation after humiliation, building up a resentment for the world that he couldn’t act on, as he was as weak as they come.That is, until he discovers a dusty grimoire in his attic. Just by opening it, a mystical power flooded his very being, fundamentally altering his body and granting him a gift unlike any other.[Creator’s Grimoire System: Activated][Starting Level: 100]Equipped with the strongest system, unrivaled and seemingly boundless in its abilities, Noah decides to take back the life he missed out on, and much more.Weaving time, rewriting the memories of those around him, and even summoning fictional heroes, there seems to be no limit to the newfound power he has gained from his system.As the world’s first supervillain, he sets his sights on world domination, but who will try and stop the godlike youth in his path?

Revenge is a dish best served cold, with dollop of whipped suffering and a sauce of acute humiliation.Karma would do anything to exact revenge on the one who was responsible for her mother's death, her father's disdain and distrust, and a miserable life.She was manipulated, maltreated, and humiliated by the one she trusted the most. Her stepsister!!Discovering she had only three days left to live, Karma would go to any length to exact revenge. Even offering herself to the scary and powerful demon overlord.A contract. Blood oath. Manipulation. Betrayal. And lots and lots of revenge.

“Why is the thing you summon always so strange, can’t it be a little more normal?”

Lu Yu looked helplessly at the guy who was waving his tentacles in front of him.

“Who made me look up to see you every day…”

- Description from novelbuddy

A con-man and policewoman that are legends of their respective professions suddenly die, then are reincarnated and return to the Tang Dynasty of ancient China as little kids.

Accepting their second chance and forced restart, they choose to use the modern knowledge and specific talents that they have in their previous lives in order to live comfortably in this new life.

- Description from Novelupdates