The rarest manifestation of brazen spheres is the Brazen Sphere Imprisoner, a form that only emerges in response to a solitary intruder. Standing at 8 feet tall, this sphere envelops the targeted intruder upon activation. Once initiated, all spheres within the vicinity roll toward the intruder at a speed of 60 feet per round, merging into the larger spherical form. The intruder can evade this enclosure by making a save vs. Dragon Breath. Failure results in the spheres creating a metallic cage around the victim, rendering them immobile. The brazen sphere imprisoner then enters a dormant state, detaining the victim until either the imprisoner is subjected to an attack or the correct command word is given to deactivate the construct.

Regrettably, most victims succumb to starvation or thirst, as those with knowledge of the command words for release are typically long-deceased.