Fantasy: Immortality Begins with Slaying Demons

The Blue Star Soldier King traveled to a different world where demons were rampant. Sitting in the system, he originally wanted to survive for ten thousand years, but he had no choice but to be trapped in the overall situation of demons. There are monster mountains and seas in front of you, and there is no one behind you. It doesn't matter, just use a pair of iron fists to fight your way to immortality!