Vanishing of the Pan'lornian Planes

Some time ago, when the war against the darkness began, many planes fell victim to a horrific phenomina called Complete Darkness. This is where a plane is enveloped with pure entropy.
There were many planes within the Cosmic region of Pan'lorne, however centuries ago they vanished into darkness. In total there were 13, now there are none. Many of them were Orcish realms. This calamity lead to the many wars and conflicts as many Orcish civilisations tried to survive as they were fractured.

The Event

Before

Pan'lorne was a thriving planar region with many communities. These societies were mostly Orcs though many other species lived among them. The Ornikai of Kan'ornik was a proud culture who valued strength, honour and wisdom.
They were mostly renowned for their craft using crude materials. Pan'lorne is said to be a place which was full of metallic resources, which is how the Ornikai also became renown for their metalwork and music.
One day, the planes within the Pan'lorne region faded away. One after the other, the bright white light which they each shined gradually dimmed to black, then eventually disappeared. To this day, nobody knows how or why exactly; however there are theories which many do believe (see Possible Causes below).

Aftermath

The wrath of what ws left of the Ornikai was immense. The clans which survived the disaster scattered and began raiding and conquering the smaller planes. Their homeplanes were lost, so they had to settle anew. Naturally, this caused other factions within the Cosmic Sea to act, thus what is now known as the Great Ornikai War began.

Possible Causes

Godly Act

Many claim this was the will of a god, whether for punishment, vengeance or as a demonstration of their powers. Taria's Order claim it was part of Taria's sister's tampering with Taria's planes. The gods, according to the Tarian faith, live in a dimension without time. Thus godly occurences within this timed dimension would seem like it has happened at random times, whereas it was merely a single instance within the timeless home of the gods.

Espionage

Kan'ornik had many allies and rivals, as many factions do. Many of the Ornikai warchiefs were very expansionistic, as they would conquer each other and often other factions too. Many Kan'ornik clans, who do roam the Cosmic Sea as nomads, still claim it was an act of war against them. Some even blame it was the work of the Alliance of the Planes, whom of which the clans mostly targeted during the Great Ornikai War.