Monster Synthesis Master - Chapter 998

In 2120, a massive gateway that connects Earth with the Otherworld replaced the Aels boulder in central Australia. The Earth, representative of science, and the Otherworld, representative of magic, subsequently made contact and two wars broke out. Both wars inflicted enormous damage on both sides, eventually leading them to choose peace negotiations, and thereby marking a thirty-year era of peaceful exchanges between Earth and the Otherworld.Even though both sides chose to coexist peacefully, they each coveted the other's benefits. With the impending arrival of the third inter-world war, Earth's Otherworld combat General Staff Headquarters decided to secretly dispatch an advance team to the Otherworld to conduct pre-war reconnaissance.As a hybrid of Earthlings and Otherworld elves, Luoer, after secretly studying and training for over twenty years in Haiya Academy, which specializes in cultivating hybrids of Earthlings and Otherworld inhabitants, will soon lead his squad into an exciting adventure in the unknown Otherworld.Swords and magic? No, this is a world of guns and magic!

When waking up, Jiang Tian found out that it was not too late.

In his previous life, Jiang Tian was a member of Jiang family in Jinling. He suffered a disgrace that was his fiancee broke off the pledge of marriage, so he had to marry into the Zhao family. Although Zhao Xueqing, his wife was the first beauty in Hangzhou, he always beat and scolded her. A few years later, he went through a family upheaval, and his loved ones died one after another. With despair, guilt and hatred, Jiang Tian jumped from a cliff. But he did not die. Instead, he started a cultivation journey for as long as ten thousand years in another space.

He became the supreme god, but he died in the process of opening up the universe. With the regret for his parents and the guilt for Zhao Xueqing, Jiang Tian, who retained several thousand years of memory, swore that he would never let his loved one suffer any grievances and injuries this time!

- Description from Novelupdates

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

500 years ago, Chen Xi was devoured by a crack in the void and was transported into a cultivation world.