Indestructible Master of The Fortress is a Manga/Manhwa/Manhua in english language, Action series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

My name is Jiang DaLi, a mediocre player in the Martial Arts Universe game, and after a few rounds, I got killed. I never thought that I would be reincarnated as a mini boss in a mountain fortress, and retain memories of my previous life. Not only that, I can also cultivate and upgrade like a player! In this life, I want to become the strongest before other players even enter the game!