The Shadow Realm

The Shadow Realm is an extremely corrupted alternate dimension which can be accessed by entering the Rift of Shadows.

Origins
The Shadow Realm was first connected with our world when Xeneon initially opened the Rift of Shadows. At first it was simply a dark, gloomy world mirroring our own, and not the horribly evil and corrupted land it is now.

Endesso's Exile
Following the Aruel Ritual, one of the surviving participants named Endesso Dreik began to be overcome by his legendary weapon, the Terror Scythe. He was clearly unable to handle its immense power, and it began to destroy him. He tried to fight against it, and being an arrogant person, refused to give up the Scythe so it could no longer effect him. It wasn't long before Endesso was entirely corrupted by his legendary weapon. He forgot his name and started calling himself Shivvok. He quickly became a menace to society, going on killing sprees and leveling entire villages without provocation.

Aurelius made no attempt to stop Endesso, even though it was clearly his fault since he had tricked Endesso into being part of the Aruel Ritual. Finally, Xeneon Xipil, using the Sword of Souls and the Gateway Daggers, managed to defeat Endesso. Xeneon forced Endesso into the Rift of Shadows, which he had opened earlier, and exiled him in the Shadow Realm. Only then did Aurelius step forward to help, offering to cast a bind on Endesso, or Shivvok as he has always been called since. This bind held Shivvok under the control of whoever controlled the Shadow Rift at the time, hence Xeneon was Shivvok's first master.

Main Article: The Night of Binding

Corruption
The most visible result of Endesso being exiled to the Shadow Realm is the corruption of the entire dimension. What was before simply a dreary, cheerless land, became a nightmarish world of desolate wastelands.

Presently the rivers and oceans are filled with poisonous muck, forests are all dead, and no life can survive for long. In addition to the natural factors, Shivvok roams the plains and kills anyone he finds, so the Shadow Realm is an extremely hazardous place to be.

Shivvok
Only one individual resides permanently in the Shadow Realm, known as Shivvok. Shivvok is generally known as the master of the Rift of Shadows, even though he was originally a human from our world named Endesso Dreik.

Sylor
Sylor Alimundi lived in the Shadow Realm for a period of time following his death at the hands of the Shadow Assassins while protecting Prince Raxus. Sylor would have been permanently dead if it weren't for the Sword of Souls, which he was weilding at the time. The Sword of Souls has the ability to keep its owner from dying completely, and instead they remain in the Shadow Realm.

Others
Other temporary inhabitants include the spirits of the deceased. The Shadow Realm seems to serve as a "between" world for recently departed spirits moving to the next world, so those that die by conventional deaths pass through it for a brief period of time.