MTL - I Have a Big Problem with My Achievement System - Chapter 463 Yunlutian, forbidden air?

This story is centered around the man named Yi Ji-Hyuk, who has spent 1000 years in a Medieval Western fantasy-like world before returning back to the modern-day Earth. When he returns, he finds that his home is facing monster threats, and that humans with superpowers have appeared to protect the innocent people of Earth.

Matthew grew up in a decent family filled up with hopes, dreams and big heart, but living a shitty life which were suddenly demised with the unexpected turn with a mishap. With the new changes of his body, he finds new powers and wondering into new dimensions. This new enigmatic power is suddenly taking soul form his body and making him something beyond of his imaginations.... His tasks are unclear but he has to take soul of each demon he meets in his path... With his powers he has bigger responsibilities in each of the dimension which is beyond explanation…

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