Anxiety Propagators are dream-realm devices dreamt up by Gulagra to assist his scions with their infiltration of the Dream Realm.
The Anxiety Propagators in the Phantom Ilmari Desert may be destroyed during the quest The Anxiety Propagators.
Phantom Ilmari Desert Location Guide
(Image credit goes to Discord user Yogi as well for providing the last location I needed which was the roof access one - Aaryonar)