Within a Hollow Heart - Chapter 119: Volume 2, : “The Fading Light”

A decade ago, the first dungeon gates appeared, but some vanished before they were ever conquered. The MC, a low-rank hunter, awakens the Lost Gate System, granting him access to these forgotten dungeons where legendary monsters and artifacts are trapped. Each completed lost gate grants him absurd power, but also reveals terrifying truths—these dungeons are prisons for ancient beings who want revenge.

After you’re awake but find yourself looking like a character in a game and came to a strange place, is this a different world or a game? Is it a rebirth or a cross over to another world? Everything needs to be explored by yourself!

- Description from Novelupdates

“I'll take this child.” Sold to the Wudang Sect's outer martial arts training hall for three silver coins at a young age, Kwak Yeon dreams of mastering supreme martial arts. But can he overcome the needle-sized gateway barely permitted to trainee instructors and rise to become a disciple of the main sect? “A true gentleman cannot stand idle in the face of injustice!” Thus begins Kwak Yeon's unyielding journey through the martial world, following the ruthless principle of “Kill Buddha, Kill Ancestors”—destroying all obstacles in his path!

After dying in an oddly anticlimactic vending machine accident, Kazuki Ren is reincarnated in the demon realm—not as a hero, not as a villain, but as the only human male student enrolled at the mysterious Academy of Ruin, a school where all the professors are demon lords and all the students are powerful, beautiful she-demons.Ren is told he has one task: survive.But there’s a catch. The Academy’s darkest secret is about to awaken, and Ren holds a hidden power that could either destroy the demon world... or rule it.Now surrounded by seductive demons with hidden motives, eldritch tomes, forbidden dungeons, and twisted exams, Ren must master his ability—or be consumed.Magic, mystery, danger, and temptation await in this dark academia harem fantasy.