So, I previously mentioned this group way back when, during the PbP Planescape games I was running - the plan was to have them be recurring antagonists, a foil to a particular character's backstory and a credible threat to the whole party.
I've decided to resurrect them, for use in other fantasy campaigns, and they might even make an appearance in the next Planescape game I run.
The Sons of Arril (AKA The Halfbreeds) are a group operating under the banner of the Xaositects in Sigil. Their membership is almost entirely demi-human - i.e. those with a mixed-race (or species) heritage, with one side being human. Half-orcs, half-elves, Genasi, Tieflings, the rare Chaotic Aasimar, any being with some non-human ancestry can join.
They follow the legendary Bard and planar adventurer, Arril - renowned the Planes over for her... prolific childbearing. The true number of her descendants is lost - some even say that she used polymorphic magic to become male and spread her lineage even further afield!
But what makes her such a role model is that none of them were full-blooded humans - Arril had a bad case of xenophilia, and sired half-orc, half-elves, even a few half-elementals and other more... unusual breeds.
So now, those who society has rejected due to their heritage flock under her banner - while she has disappeared into myth, those who are in turn descended from her children started up as almost a support group - to help those who couldn't fit in make a new life for themselves. By now, that original membership is mostly gone, and the group has turned into something of a personality cult.
Some even say that the Sons are looking to get Arril raised as a Power - a Goddess of Half-Breeds, of Waifs and Strays... but that would take a lot of worship. Or, the divine essence of a True God...
Kirrish is one of the troublemakers of the group. More concerned with using it for his own purposes, he is most often seen as the ringleader of any "action" the group might see. He's definitely smarter than the average Xaosman - he will use scramblespeak when around other Xaositects, or when around Clueless to confuse them, but is more than capable of throwing off the barmy and performing long and complicated campaigns of subterfuge and deciet to further his own goals (and occasionally, those of the Sons). A Spellscale, he has a natural aptitude for magic and magical devices, but has no true training in the arcane. His obvious draconic lineage (his skin is scaly in patches, and has a blue-ish iridescence about him) makes some suspect that he is descended from Arkhir, Arril's half-dragon daughter, once one of the fairest and most well-known of the original Sons - and they would be right. Not that he knows that, of course!
Not as Barmy As He Looks (5)
Xaosman When He Wants To Be (3)
A Little Bit of Dragon, A Little Bit of Everything Else (2)
The Sons have organised a Mixed-Race pride march - Xaositects might support it, but they also follow in its wake, causing havoc and destruction. Find a peaceful answer, and help out with species relations in Sigil, or take the Harmonium route and go bash some heads, coming across as massive racists? Your call.
Some claim there's more to their attempt at ascension than they're letting on - by allowing Arril to ascend, some of the higher-ups hope this will either make them retroactively part-divine, or that they will be chosen as Her heralds and Proxies in the mortal world. Now, picture that power in the hands of Xaositects. See the problem? It's up to you to either stop them, or put someone more responsible in charge, before it turns into a cosmic debacle!