The coven is an ancient group of hags known for their influence in the Feywild. The group consists of 9 members. Each are legendary creatures. Many tales have been written about them.
Although the 9 members are always mentioned as one they rarely ever interact with one-another. The Coven comes together once every millenium. On this occasion they set a goal and achieve it. This goal can be anything. The only criteria is that it must be a huge unmissable visible effect. If they want to take down a Demon Lord it must die with an enormous flash visible from around the world.
The Coven has existed for as long as any living creature can remember. It is an ancient group shrouded in mystery. The reason why The Coven was created is a tale very few know. When the world was just a few thousand years old the 9 hags were just 9 sisters. A world changing event happened back then. Cegilune the god of hags was dying. Cegilune tried to take over the material plane by manipulating all of the hags in the world to create a coven and perform a ritual that is capable of harming even a god. The other gods however foresaw this and unified against Cegilune.
Ceguline, cast a spell just before her death and split her soul in 9, transmitting each to the first creature it found, so she may never truly die. The 9 sisters were out playing in the field when 9 dark lightning bolt struck every one of them. The villagers immediately ran to help the kids but there was nothing that could be done. The 9 little girls are no more. Their identity has changed forever. Because of the strong magical effect the village became one with the Feywild in just a few hours after the lightnings.
A few hundred years had to pass before the newborn hags learned their powers and their purpose. Which is to not allow humans to forget about hags and witches. The village now part of the Feywild became dark and gloomy. The plants grew black spikes. A part of the Feywild became forever tainted by the hags. The nine have come to the conclusion of splitting up being their best way to approach things. However every once in a while they should perform a ground shaking ritual.