The Formerly Number One Ranked Rookie

After learning that he can make money by clearing a full-dive VR game called Prophecy Online, Ray Endo bets his life on the game in hopes of striking it rich. When he successfully clears the game, it suddenly announces its shutdown. However, days later, the world is on the brink of destruction by the same monsters from Prophecy Online. As the only person who has cleared the game and knows its ins and outs, Ray decides to seize this opportunity and profit from his power and knowledge.

(Source: WEBTOONS)