This will be the first part; there are three things Kabal of the Jade Dragons, Wych Cult of cursed shadow and the coven called pleasures of mutation.
Origin: the coven called the pleasures of mutation started during Vects rise to power. During the attack from the space marines a haemonculus by the name of Yilliach who was part of the Coven with no name was killed by Vects goons . His personal wracks came to save him and took him back to his lair where he was put into a regeneration tube right in front of the most painful torture chamber. After not long he came back to life, but not looking the same having had multiple mutations while in there. He had 4 arms, a huge elongated spine, and spines coming out everywhere. He believed that was going to happen and that it was blessing. Not long after he came out he found out that his original coven had been destroyed and all that was left was his personal lair, 20 pain engines, 1000 wracks, 250 grotesques and about 100 vehicles. He became very angry and wanted to kill who ever did this, and then he remembered that it was the most powerful figure in the Dark City of Commoragh, Lord Absuduel Vect. In the time not long after he began to rebuild and began to conduct raids for slaves so he could muster his forces. He did and now they are one of the most powerful Covens having made deals with some of the other major kabals, wych cults and covens. All of which have undying hatred for Vect.
Specializations tactics:
The Pleasures of mutation like to use tactics that make them have the most pleasure. They
like to cause as much fear and confusion as possible before they strike hard and fast killing everything they can before leaving with enough slaves that their raiders can barely fly.
They specialize in making very ugly and hideous creations that are often very strong and cause tons of fear. Also they like to use tons of pain engine that are geared for causing the most pain and destruction as possible. They like to get as close as possible making the enemy fear dying which then makes them stronger.
Initiations and rituals: The only way you can join the Coven is if your original coven was destroyed or they made you. A ritual they do is take the Bone out of their slaves and make their vehicles armor and vehicles out of it.
I hope you enjoyed please let me know my grammer isn't that good.
Cheers