MTL - Yu-Gi-Oh!: Underworld Boss, Cancerous Creator God - Chapter 271

Ning Yechen used to be the Demon Lord. He singlehandedly took over the Demon Realm and attacked the Heavenly Realm. His name preceded him throughout the Six Realms. He got tired of fighting, so he quietly went into seclusion and became a happy hermit.One night, an Empress from the Heavenly Realm fell into the Mortal Realm after someone drugged her with an aphrodisiac. She inadvertently fell into his room, and they made out. After the deed, the Empress quietly left. Just when he thought he would never see her again, she showed up in front of him ten years later, bringing a child, saying it was his daughter and demanding accountability from him! “She’s your daughter. You have to be responsible for us!” Ning Yechen was stunned!

Juvenile Qin Chen, the star gate was taken, repaired as abolished, but it was awakened to the memory of the nine ninth, and opened the tenth journey of the sky. Wanjie is a book, I write a pen and write a thousand worlds. The hundred fields are mountains, my heart is the sea, and I walk out of the heavens. Hand Optimus, foot on the ground, this world, I am the emperor, who, dare not to accept?

- Description from sobiquge.com

A skilled but unfortunate modern-day assassin was killed in a freak accident. However, he soon found himself summoned to another world by an evil wizard, who had him possess the body of a boy as an experiment. After successfully planning the evil wizard’s downfall, he used the wizard’s body as a springboard to gain influence and power in his new world.

- Description from Novelupdates

mc gets transmigrated to Fallout New Vegas with the merchant system. let the questionable adventure begin.