Schandian Onder Realm

Description
The Onder Realm is a very dark, shadow-covered plane. Rolling hills and a few mountains dot the landscape. Rivers run red, and trees have green trunks with white liquid-like leaves. There is a trace of sunlight every so often, but it's rare to come by. Small towns and a few large cities of Shadow-walkers spice up the land. Large demon-beasts called Hagilkhan act as brutish slaves for fighting and mining. It's a desolate plane, and when not in safety of a community, it's very deadly.

Inhabitants
Shadow-Walkers: These are humanoid shady creatures. They have porcelain white faces with black spherical eyes, and a black set of lips and ears. They have dark, wispy black bodies. Their form shifts and moves as they live. They're humans taken to the Onder Realm by the Four Darklords of Schandian. Shadow-walkers have no souls. They lose their souls when they're taken and bound to the Onder Realm.

Azerden: Azerden are similar in shape to hands. They're green with white spots. They're small and have a round main body, with three front legs and two legs in the back. They creep up on shadow-walkers and humans, and attempt to launch into their body, usually through the leg or back. They are parasitic, and nest in the host's body for a long time. If they're a human, they're slowly turned shadow-walker. If they're shadow-walker, they're slowly killed. There's a few signs that you can use to tell if you've got an Azerden in you. You'll feel rashes sometimes where it's located. In the beginning, you'll get migraines and your leg might feel numb.

Rengun: Rengun are the dead shadwow-walkers. They serve a Darklord and go to the material plane to consume humans for the Darklords. They appear as thick shadows, tugging at legs and feet of creatures, pulling them down into the ground. They slowly sink them into the ground and into the Onder Realm.

Hagilkhan: Creatures of immense size and stature, with muscular arms the size of the tallest & biggest human combined would describe a Hagilkhan. They're somewhat uncommon, but most of them are in slavery. A native, untouched Hagilkhan is rare, and dangerous too. They often make huge green-wood clubs. They're often around forty-fifty feet tall, and are a few tons.

Shade-Wyvern: Large, thin, wispy Wyverns that may roam free or serve a Darklord. These large beasts are considered rare, and the only true material possession they have is their claws, which are sought after by Shadow-Walker Merchants, fetching a pretty penny. The Shade-Wyvern is a reclusive beast, often venturing out once a month for a meal, which can vary in size from a Rengun to a Hagilkhan.

The Four Darklords of Schandian
The Four Darklords are the rulers of the Schandian Onder realm. They rule different provinces of the realm. They feast on the souls of humans, and grow in size from it. The largest Darklord is thought to have around a dozen million souls in him. The smallest has just around a million and a half. They take out cities at a time on the material plane, killing thousands every day to just keep on growing in power and size.

The Darklords are often at war, but sometimes they cooperate with one another. When this happens, they benefit but humankind suffers. They don't destroy cities at a time, they destroy provinces and kingdoms at a time when working together. They gain hundreds of thousands of souls. They gain new armies of Rengun, new Hagilkhan slaves, and more power with the souls. They are the tyrants of tyranny.

History
The Four Darklords used to exist on the material plane, except they had another Darklord, one so huge he ruled all the others. The Fifth, the biggest, was unimaginably powerful and strong. He could destroy continents. He destroyed a few planets, even. He ruled with an iron fist inside an iron glove. He oppressed the other Darklords, claiming all of their territory for his own. His Rengun were far more powerful than the others' and they brawled and the Fifth's army one.Eventually, the four other Darklords got tired of it. They conspired, and rebelled. They eventually beat the fifth but they were all reduced to barely any power.

In this power-loss, billions of souls were trying to enter the afterlife all at once. The afterlife couldn't take the sudden shift, and it deferred the souls into a smaller space it created, the size of a continent and a few large island chains, and a sub-continent. The souls populated the place, creating the Schandian Plane. The Darklords went there, and killed many Shadow-Walkers, consuming them and making them into Rengun.

After a couple decades, there was no Shadow-Walker left with a soul. They could look outwards now. They began their pillaging and raiding of the material plain again, and in full force. With Renguns at their side, they could attack a dozen places at a time. This made the Darklords' armies vast killing machines built to feed their associated Darklord.