Yeongung, Hoegwihada

With the unexplained emergence of dungeons came a relentless onslaught of monsters that overwhelmed humanity. Even the Awakened, humans with special abilities to fight monsters, couldn’t stop the destruction of the world. In the end, only Seong-In Kim, the most powerful Awakened, was left standing. Upon his death, Seong-In wakes up twenty years in the past as an unassuming high school student named Su-Hyeon Kim. He’s not sure how or why he was brought back, but he does know this is his second chance to save the world and redeem himself as a hero.

(Source: Tapas, edited)