The Level 0 Demon Lord

In previous life, Rezvan was so pessimistic and believed himself that he was so inferior in many things, so he was so easily used in his workplace. Now, Rezvan reincarnated and became Demon Lord in the middle of the woods with a system beside him. The status showed Rezvan’s level is 0 but it seemed the status window flickered. The system didn’t catch it and believed he was level 0. He got a mission to get out of the woods, but after he stepped foot outside the woods, the Revival of Demon Lord spread entire world, because he was level 0 and his pessimistic character decided to live in the woods so the world didn’t know about the revival of Demon Lord. But the woods that he lived in were deadly woods, where all the deadly monsters, plants, and even insects live. How will the main character build his own world and what is the meaning of flickering in his status?