Using Blades in the Dark to develop NPC Adversaries?

So I’m currently running an Ars Magica Campaign set in the time of the first Crusade. I’m running with a single player who rose through the ranks and carved out the Frankish Principality of Damascus, in a highly alternate history. The PC has made many enemies, both inside The Order of Hermes (the premier society of wizards of Europe), The Summoners of Solomon (the primier society of wizards in the Middle East). An interesting note is the PC is faking being his own twin brother: “Prince Aubert of Damascus” (formerly Avranches, Normandy) and “Kaldus of House Tytalus of the Order of Hermes.”

Enemies who will be using the criminal underworld against him, via the Banu Sasan. There’s a fair amount of medieval research I’ll be doing, and after recently reading Blades in the Dark this has given me lots of ideas to use for these NPCs in my campaign.

I’m wondering if anyone has used Blades in the Dark for NPCs and organizations in other campaigns using other rule systems?

Or, just if anyone has any ideas or advice to suggest. I’m not picky and welcome anything.

I have not, but you can always read through BitD and steal ideas for various factions and NPCs.