Great reads (little to no romance)

I like this one a lot.The MC, lives in a world where mysterious realms called "shadow worlds" suddenly appear. If a shadow world isn't "conquered" quickly, it devours the city/civilisation it opened in, which later becomes nothing more than a part of history. In addition, the world is well devided between nobles and commoners. MC was a commoner who got stuck in a shadow realm for 13 years before dying. He goes back in time and is determined to change the course of things

This manhwa is sooo cool!!
In the world of the awakened, Kayden is the strongest ability user. Not a day goes by without him fighting with his life on the line. One day, as he's injured and in a dire situation, there's no where to run from his enemies, in despair, he transforms into a cat and is picked up by Jiwoo, an awakened teenager with an incredible ability. Things happen and Kayden takes Jiwoo as his disciple.