The CEO's Substitute Wife Is A Genius - Chapter 418: Morning Sickness?

After being transported to this world, Nara Kazuki discovered that as long as he grinded enough proficiency, his jutsu could level up.And so, he began walking a very... peculiar ninja path.

Zheng Tan somehow returns to the year 2003, turning into a black cat. Picked up from a rubbish heap by the Jiao family, he is given the name “Charcoal”, and so begins the life inside Professor Jiao’s family. Zheng Tan remembers that he was once a person, but currently his body is that of a cat. He has no way of speaking the human language, but can understand it, and even retains the thinking and IQ of a young 20 year old youth. Read along as he adapts to this new world, and somehow tumbles from a group brawl to catching a thief.

- Description from Novelupdates

Choi Hyun-seok, a heavyweight champion of the biggest mixed martial arts league on Earth and the one who was called the strongest had died.Afterwards, he was granted new life as a hero in another world.‘Wealth! Honor! Endless beauties at your fingertips!’With thoughts of such a dazzling future, the first thing that he saw when he came to this new world was a towering ox monster.The monster, who was the commander of the demon army, asked.“Hero? You’re saying you’re the hero?”“Uh…I think…?”And so, that was the start of hell.