Marietta-hime no Konrei - Chapter 10 The Unmindful Princess

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

Jiang Bai woke up one day and found with shock that he had transmigrated to a parallel world that is similar to Earth. There, he was granted a cheat system to help him forge the path of a tyrant in this new world. He was now stuck in this parallel world body, the body of a weak and cowardly person. Join Jiang Bai as he rose to the top in this new world!

- Description from Novelupdates

Juvenile Luo Yang, because of the body being blocked by evil dragons, and with the blood of God, has embarked on a road to heaven! Rise from the humble, turn the mountains and seas, step into the world, and press the heavens!

- Description from 69shu translation

Seven billion humans living on the Earth time-traveled together after they had woken up one morning. They all heard a synthesized female voice.