The Kabal of the Three Exquisite Sorrows.

So, my friendly local gaming store is starting to run a 40K league. While not exactly a tournament, they're going to keep track of wins and losses and make a vague story out of it. So I thought it to be wise to flesh out what exactly I had.
Thus far, in my two and a half years of evil-space-elfing, all I have is the name (The Kabal of the Three Exquisite Sorrows) and the fact that it's obscenely rich because they discovered (stole) a poison that rusts the living metal on Necrons. They sell it to the rest of Commorragh.

Think I should include anything else?

Well, coming up with names for the archon and other important personnel is always good.
That way, the other races know who to fear!
Good thing to know also is that why is the kabal named like that.

After a long and thoughtful shower, I thought of this;

The Kabal of the Three exquisite Sorrows is led by Archon Alkex Celebron. Though most of Commorrite society knows him as "The Art Dealer" Alkex has a passion for pre-fall artifacts and technology, and as such he spends as much of his fortune on funding expeditions to crone worlds and raiding tombs as he does on realspace raids and sponsoring wych cults. Alkex employs his kabal to find any kind of artifact. Weapons systems and esoteric poisons are just as welcome as fashionable clothes or even secret passages and gates in the webway.
To find the objects of his desire, he and his kabal maintain a massive intelligence network encompassing various corsair fleets. The Kabal of the Three Exquisite Sorrows pays handsomely to those who can verify the location of useful artifacts. As such, corsairs or other thrill seekers often visit the Three Exquisite Sorrow estate in Low Commorragh.
As one would expect, having that many valuable ancient Eldar artifacts in one place would draw a great deal of thieves and glory seekers, eager to claim the prizes of the inner sanctums of the Kabal. Thus far, none who enter without permission have left with their lives. Their bodies hand delivered to their closest relations by scourges in gilded boxes, piece by piece over the next 72 hours.
The Kabal of the Three Exquisite Sorrows is named so because of the three secret rites a prospective initiate must endure before becoming a fully fledged Kabalite warrior. Only the first of which is common knowledge on the streets. A young Dark Eldar must enter the webway or the catacombs of low Commorragh and return with something interesting. If the thing they find peaks the interest of a dracon or even the Archon himself the prospective initiate will be ushered into the second and third tests. Should they succeed they will emerge a warrior of the Kabal. What happens to those who fail is yet unknown.
To date, the most impressive of the Kabal of the Three Exquisite Sorrows escapades was the stealing of the compound that rusts Necron living metal. This act forever earned the Kabal the enmity of the Alaitoc craftworld. The Alaitoc rangers had planned on delivering it to the craftworld, so that they might share it amongst the other craftworlds and they would all benefit from the weapon. The Archon Celebron saw a chance for personally leading a host of Kabalite warriors and trueborn against the Alaitoc rangers, ambushing them and stealing away both the compound and the rangers.

What else would you include?