On the planet called Earth, more than two billion people live there. Originally, the Earth's population was ten billion in number.

However, it changes when the purge is happening.

What is the purge, you may ask? The purge is the day where more than eight billion people on the Earth are dead. The reason? The Dungeon.

What is a dungeon? A dungeon is a pocket dimension filled with monsters. A dungeon is connected by a portal that appears in a random area. That did not sound bad, right? Wrong.

When the dungeon appears, it releases wave after wave of monsters from the portal. That monster is the one called the Agent of the Purge. That day the Earth got bathed by a river of blood from all the humans killed by the monster.

Lucky for the people on the Earth, when the purge started, they got a system. Coming along this system is an Innate Ability. With these innate abilities, the humans have a chance of pushing back the monster in their homeland.

For the next twenty years, the people on Earth fight the monster that is roaming the land, and it takes another ten years to rebuild what has been destroyed. Even then, some of the areas cannot be recovered.

Many islands become inhabitable because of the monsters roaming on the islands.

That thirty-year period is called the Reclamation and Rebuilding era.

After that era, a new era was born. An era called the Golden Age of Hunting. The people that go inside the dungeon are called hunters. A hunter generally gets divided into three categories. Attacking, Defending, and Support hunter.

Attacking is a hunter whose primary purpose is to attack the monster and kill it as fast as possible. They can attack from either a close range or long range.

Defending is the opposite of the attacking hunter. They are the ones that get the monster's attention and keep its attention on them. Not only that, but they also block any attack that goes to their ally.

Support hunters are the people that help the other two types in their fight. They usually help the other two by healing, buffing, debuffing, or supplying information.

All those hunters aim for one thing when they decide to risk their lives in the dungeon: power and riches. The dungeon is filled with riches in the form of Feraklinium. Feraklinium is a crystal that grows in the dungeon.

Before we go to this crystal, let me tell you the energy that awakened when the purge day happened. This energy is called mana. Mana can be used to enchant one body and to cast a long-range attack.

Feraklinium is a crystal that contains mana.

All of the technology is not working inside the dungeon unless that said technology has been modified. Machinery, guns, and even handphones. Because of this, the weapon used to clear the dungeon is usually a medieval type of weapon like sword, spear, and ax.

There are a few exceptions, like a magic gun. A gun that has been modified to work inside a dungeon. Sadly, it is a fuel-hungry gun. It needs a ton of Feraklinium crystal for it to work as long as needed to clear the dungeon.

Other than that crystal, the dungeon also drops loot in the form of equipment and crafting material. The equipment is usually dropped by a mini-boss or boss monster, and all that equipment is usually already enchanted.

The system will tell what kind of enchantment the weapon has.

Crafting material from the monster can be used to make armor and weapons. Not only crafting material, but the dungeon also drops edible material like meat or even flour.

The edible material from the dungeon can be used to cook some food, and the food cooked using this material will provide a boost to the one eating it. All those things cost a fortune. This is another reason why many hunters decide to risk their lives in the dungeon.

Speaking of hunters, a hunter is divided into seven ranks. F-class, E-class, D-class, C-class, B-class, A-class, and S-class.

A new hunter will go through a screening where they will go through a test. The first one is their mana testing, where a machine will scan their mana capacity, and the potential someone holds. After that, they will be tested on a physical machine. This machine will test their strength, speed, and endurance. The last test is a support compatibility test. The hunter will be tested if they have compatibility to a healing spell by learning it and casting it.

F-rank hunter is not the one killing the monster. No. They are more of a miner that mines the crystal inside the dungeon and carries them outside than a hunter. They are the one that helps the hunter that fights the monster by carrying their equipment and loot.

An F-rank hunter can grow to an E-rank hunter or maybe a D-rank hunter, but it takes a long time, and too much material is needed to do so. Because of this, many F-rank decide to accept their fate as a forever F-rank.

One of those people is Rio Renaldi. Rio is a twenty-three-year-old who lives in the safer part of Jakarta, Indonesia.

He is an F-rank hunter, but he is a retired one. He spent three years of his life becoming a miner inside the dungeon. Rio is your ordinary man on the outside, but on the inside, he is different.

The difference?

"Urgh. Twenty-three, almost twenty-four, years since I got into this world and I am still stuck at a crappy job."

Rio is a reincarnated man from an alternate earth. He is a manager in a supermarket near his house. One day, when he was sorting the item inside the storeroom, one of the shelves fell on him, and his head got crushed by a heavy item.

He thought that he would get to hell or heaven, but Rio got reincarnated into a baby to his surprise.

When he reached the age of seven, Rio realized that this world was different from his world, and he realized that this world was even more dangerous than his previous world.

When he reached the age of twenty, Rio decided to become a hunter in the hope of getting a large amount of money, even when his parents did not want him to join the Hunter corps. They said that he would get disappointed.

True to their words, Rio was disappointed when he got the result of the test. He is an F-rank hunter with an unknown ability called the Aura Kingdom. The hunter association deemed that ability is not good enough to raise him to a low E-rank.

Because of that, Rio became a miner. After three years, he decided he wanted to retire and open up a store.

Right now, he just got back from his mining job and is getting ready to send his resignation letter to the hunter association.

Just as he sits down on the couch, he opens up his system.

Rio looked at the panel in front of him with a surprised expression. His stats are different from yesterday. The innate ability section has changed from yesterday. There is no waiting notification besides his innate ability.

Rio presses his innate ability and gets greeted by another panel.

Rio quickly pressed the Y button before suddenly darkness consumed him.