One Piece: Human God - Chapter 31: Sky Island Fight II

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.

MOUNTAIN SITTING IMMORTAL (MSI)A conduit of the great Dao happened to enter the grotto heaven called Earth. No one had been able to take ownership of this conduit for many years until Marvin came into contact with it. Marvin met the requirement to use the conduit. This allowed him to begin his journey towards immortality. The journey begins from transcending the first mortal coil at Body Forging to transcending the second at Energy Gathering, passing through the subsequent mortal coils, and hopefully to becoming a true immortal with eternal life.But the conduit is far more useful than helping a dying business tycoon gain another lease at life. It is also a conduit of great power. This power and many more will be his as long as he continues to sit on his mountain and grows the mountain into a colossus. The mountain will bring him to greater heights and greater power. This is the story of the Mountain Sitting Immortal.

In the City of Crime, one law stands above them all: Only the strongest can live.

When the natural disasters come, the whole people travel through the wasteland world and face the challenge of death and survival!

Horrible acid rain, monstrous floods, sky-burning cities, global glaciers, super radiation…

No one is immune!

To survive, human beings can only build shelters and accept rounds of baptisms of natural disasters.

Fortunately, Somo awakened the doomsday survival system!

His refuge can be upgraded infinitely!

【Wooden Door】→【Iron Door】→【Alloy Gate】→…..

【Wooden Spear】→【Literwood Spear】→【Electromagnetic Spear】→…..

【Diesel generator】→【Bio generator】→【Thermoelectric generator】→…..

When everyone was rushing to prepare for the next disaster, Somo was already fully equipped and rampaged through the wasteland world.

“We’re still lighting the oil lamp, and they all use the refrigerator!”

“His refuge is said that the walls are tens of meters thick and it is the safest place in the world.”

“In my lifetime, I want to live in the Sushen Refuge for one day”

- Description from novelbuddy