Olivia Darque is assistant to Marshal Brass of Cap Au Diable in the Rogue Isles. Olivia is only seen on few missions and rarely mentioned, however she is still seen as one of the more important officers of Arachnos partially because she manages Cap-Au-Diable, one of the most busy cities within the Rogue Isles and partially because she is sidekick to Marshall Brass, one of the most decorated Arachnos soldiers who is not an Arbiter or within Lord Recluse's inner circle.

Some time ago the mad scientist named Doctor Aeon was made Governor of Cap-Au-Diable. But Aeon seemed more concerned with his experiments than the boring hum-drum day-to-day and usually neglects his political duties; To this end Marshal Brass and Olivia Darque run the city on the day to day. Brass attends to military and security matters as well as high-priority details from Lord Recluse's special projects while Olivia handles the more mundane politics of Cap-Au-Diable and Aeon City in particular as it's mayor. Olivia seems to operate as a more real-world politician than most super-villains within Arachnos, she just happens to make most of her policies happen by complying with hardened super villains; Yet there is more to Olivia than meets the eye. Olivia has dark powers, the origins of which are unknown but she can shoot blasts of negative energy from her bare-hands and create black tendrils that grab and immobilize her targets. Olivia uses the clout of her office and her ties to Marshal Brass to build her own prowess despite her less than notable super-villain presence within the Rogue Isles.