When there is Light, there's bound to have Darkness to let the Light shine its brightest. The Element Darkness originates from the Abyss Of Stars. This was a galaxy that was filled with Dark Matter, looking like the Void. It barely has any planets and life was scarce there as well.
No Mage wanted to come close to that Galaxy, where there was nothing but pitch black. When Mages entered it, they were never to be seen again. This was used by the Council to be a dumping ground for beings that violated the rules and regulations of the Universe.
Think of that area in the Universe as a prison ground. The area was so dense with the darkness that even the mighty Valkyries would fear it. Multiple worlds have asked them to clear that area but Valokia refused to do so. No one could blame them, it was larger than Valokia itself.
But when a planet was born within the Abyss of Stars started to show signs of life, the Council caught on and sent a few Mages down to check. However, these new lives were hostile, harboring the Element of Darkness and using against anyone who dared tread into their territory.
But the ones from the Council weren't the first to arrive. It was some other Mages that set foot first. The dwellers of this new planet called themselves 'Shadows'. In the beginning, they could not feel or think. They barely qualified as having 'life'. That was until invaders came.
Tired of being ignored and seeing their home being trampled to be something else, these shadows became sentient and fought the invaders by swallowing them whole. This then gave them form to live and breathe in. And to defend their home in. This planet was known later as the Shadow Tribe.
Eventually, the Shadows made peace with the Council and continued with their daily lives as Dark Mages. And the Council made sure that the Valkyrie and the Shadows would not have any encounters with each other, even if they called for a meeting.
The Element of Darkness is the backbones of dangerous Elements, such as the Element of Necrosis, Fear, and anything evil or destructive that the Mages could come up with. This Element requires the user's or surrounding people's negative emotions to power their spells.
Representing Death itself, most Mages feared to use this Element as it was dangerous to both themselves and the people around them. Only a small handful dared to make derivatives of it, used when the Mages can control it.
When this Element gets out of hand, the damage that could be done would be detrimental. It could decimate worlds and toss people into the Abyss. And this Element is known to have Area of Effect spells.
Though the Shadows were hostile at first, as the years flew by, they learned how to control themselves and work with others. And after a few years, they've managed to send a representative to listen and attend a meeting with the Council.
This shocked the world when the leader of the Shadows, known as the Sovereign, showed up to a meeting one day and shook hands with the Empress of Tenacity at the same meeting table. It was about how the Darkness Element had been rampant throughout the Universe.
The Shadows were willing to share more information on how to control that power and this resulted in the first set of Magecraft called the 'Alter Form'. Where a spell would be tainted by the Element of Darkness to increase the spell's strength.
This was based on the fact that the Element of Darkness focused most on the negative part of the user to channel it into damage and destruction. The basic spells of this Element have no healing or defensive moves. All of them were meant to use as attacking spells.
Thus, by mixing in the Element of Darkness with their spell, the user would enhance the damage being dealt by a significant amount. That was the initial plan. But as time went on, the term for Altered Spells took on another meaning. It introduced spells that have been flipped.
The spells would need to be the opposite of what it was supposed to be. For instance, the Okeanos spell from Heaven's Wheel of Valokia has an Altered Form, called 'Black Ocean'. The difference is that Okeanos is used to purify the area's dwellers.
Black Ocean enhances the dweller's negative thoughts. Thoughts of evil and invoking violence within them. This Element was rumored to be the foundation of the Element that would be later known to wipe out most of the Universe, the Element of Corruption.
The Element of Darkness is common but the true Founding Element is called the Element of Abyss. Where they could turn others into nothing.