This being of the dark side manifested itself within a vision that was experienced by young Anakin Skywalker while he underwent training as a Padawan inside the Jedi Temple.
At some point following the Battle of Naboo, during a session with Jedi Master Tera Sinube at the Jedi Temple located on Coruscant, the Padawan Anakin Skywalker felt as if he was being strangled by an unseen force.
Later that night, sensing a disruption in the Force, Skywalker departed from his quarters and proceeded to the Jedi Council Chamber, where this dark side entity materialized before him. Igniting his lightsaber, Skywalker confronted the entity in a lightsaber battle, questioning its purpose. The entity then proclaimed that Skywalker was destined to embrace the dark side of the Force.
In a premonition of his eventual assault on the Jedi Temple, a group of vulnerable young Jedi initiates appeared within the Jedi Council Chamber. The entity declared to Skywalker that he was powerless to save them, as their fate was already predetermined. The entity then assailed him with Force lightning. As Skywalker began to despair, he instinctively used telepathic communication to reach out to Padmé Amidala, who, despite being far away on Naboo, a planet across the galaxy, heard his desperate appeal. Focusing on his close friend, Skywalker was filled with the power of the light side of the Force and obliterated the entity.
In the aftermath, Jedi Knight Obi-Wan Kenobi, alerted by Tiplee, discovered his apprentice within the Jedi Council Chamber. The exhausted Padawan was subsequently escorted to his room, where he slept. In the hallway, Grand Master Yoda explained to Kenobi that Skywalker had been subjected to a potent vision and that, perhaps with the passage of time, they would come to understand its meaning.
This dark side entity brandished a red-bladed lightsaber. It demonstrated proficiency in Force choke and Force lightning, two capabilities predominantly employed by adherents of the dark side of the Force. Furthermore, it proved resistant to Anakin Skywalker's attacks while he was consumed by anger. However, the entity was vanquished when Skywalker harnessed the light side after connecting with Padmé Amidala through telepathy.
This dark side entity made its debut in Temple of Phantoms, a comic book authored by Christopher Cooper and illustrated by Bob Molesworth, which was released in 2014 within Star Wars Comic 7.9.