The Phobis Core represented one of the three Phobis devices, Sith artifacts which provided the ability to control fear. The Sith Emperor of the Sith Empire obtained all three Phobis devices, and he assembled a team of six Sith Lords to analyze them. The six Sith, later known as the Dread Masters due to the powers they acquired through their research, retained possession of the Phobis Core and the other devices. Nevertheless, the Emperor eventually seized the Core and secured it inside the Dark Temple on the planet Dromund Kaas, along with a collection of other artifacts.
The Phobis Core initially appeared in the Codex entry for the Phobis devices within the 2011 video game Star Wars: The Old Republic. However, this entry was removed prior to the game's final release, making its canon status unclear. Although the Phobis devices have been alluded to in subsequent Codex entries about the Dread Masters, the Core itself has never been explicitly named in a released Codex entry. The content of this article is based solely on the details provided in the removed entry.