MTL - The Whole Live Room is Knocking Me and the Female Partner’s CP - Chapter 21 Look like

The world had changed when the System arrived, alongside the Cataclysm that filled the world with monsters. The technology was gone, replaced by classes and skills that allowed the people to fight back. When Devon ended up as a Blacksmith, a class that didn’t grant Intelligence, he had to face the reality, that his old career that he loved - mathematical sociologist - was over. Instead, he had ended up as yet another discarded member of the production class, overshadowed by the existence of the System Shops to the point of total marginalization. But, what if all he needed was to reapply his scientific thinking to the System...

The mentally disabled 13 year old daughter of the Ye family, one day re-births! She rules over the Omnipotent God’s Cauldron, she possesses a spirit cultivation space. She’s no longer the good-for-nothing, abandoned girl who everyone bullies whenever they see her! With her incomparable poisons, even miracle doctors have to move to the side.

Spirit beasts beg for contracts, but too bad, even the God of Beasts have to call her Boss. Scum father, you dare to abandon your wife and daughter, she will surely make him destitute and homeless. People of the world, you dare to bully her, to insult her, she will definitely pay them back a hundredfold.

Reborn again into the world, she returns as a sovereign, but who knew she would attract the nefarious-blood-thirsty-demon him. He’s definitely the sly emperor who doesn’t hesitate to kill and cut down anyone, but he transforms into a harmless foolishly cute prisoner prince of an enemy country……

- Description from novelupdates

Crossing to One Piece world, he became Roger’s younger brother.

During the demon-summoning ceremony, Aiwass finally recalled his past life's memories.This should be an online game that his family's company had released and operated for six years. Now, his foster father was the leader of the latest version's antagonist organization.He would expose his identity six years later, hesitate and then defect from the protagonist's side. Ultimately, because he decided to take a fatal strike meant for the player character, he was killed by his upright older brother in a transitional CG without even a chance to enter the main content.——But the problem was not too significant. Aiwass also knew many secret advancement routes exclusive to the player character, as well as the Nurturing Secret Sequel regulations of the various Paths. He believed he could reverse his unfortunate fate……So now there was only one issue left.“According to the original plot, shouldn't I have been rescued by the protagonist before this lousy ceremony even began?”Tied to the ceremonial altar as a sacrifice, Aiwass fell into contemplation.