Skeleton Knight, in Another World - Chapter 17Volume 6 -

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

What is a genius? Capable of comprehending any battle skill regardless of the skill itself and sweeping away the bottlenecks while cultivating a new technique; this is a true genius! He Yiming was originally an ordinary youngster in the He family’s estate with not too extraordinary aptitude in learning martial arts.

However, after a fortuitous encounter, this ordinary youngster became what people refer to as genius in a single leap. Possessing an aptitude for learning martial arts which would leave people in awe, regardless of whether it’s his clan’s Houtian Scripture of Five Phases or various Xiantian scriptures of legends. Regardless of whether it’s mental techniques or battle skills, he can comprehend them all in their entirety at a frightening speed. Martial God, with martial as its name, using the most simple and direct approach, thrives!

- Description from Novelupdates

If you had the chance to go back a few years, relive your life, and rewrite your story—armed with a mysterious system designed to help you achieve your dreams—what would you do?This is the tale of Park Adan, a boy who met a tragic and humiliating end, crushed by a falling billboard on his way home. But fate wasn’t done with him yet.Adan wakes up in his bed, three years in the past, with a second chance to change everything. And this time, he’s not alone. With a system to guide him, his journey to rewrite his life begins—filled with challenges, opportunities, and a quest for redemption.Will he succeed in shaping the future he desires, or will the past catch up with him again?

Long Fei, a cross-timer and doujin, is an otaku who traveled to another world. In the original world, he was an otaku fan of Gundam and military science fiction.

He died in an accident and was reincarnated into another world. The Gundam works he had read before his death and the techniques in various military novels could be brought to another world.

How would he use the Gundam that Long Fei created? What waves can be caused in this different world?

- Description from novelbuddy