|Wall of light|
A Wall of light was an immense Force power used by Jedi. Though similar to the Jedi ability Force Light, this ability was unique in that it required the collective focus of multiple Jedi, simultaneously channeling their Force power into a single, devastating attack. Using the light side of the Force, the group of Jedi could create a wall of light side energy, that effectively traps the dark side spirit or taint within a specific location. When used against an individual, the power was similar to blocking one's connection to the Force, and could either be a temporary confinement or a permanent blockage. This ability required a great concentration of light side power, as it could have potentially deleterious results.
During the Great Sith War's battle for Coruscant, Sith Lord Ulic Qel-Droma was betrayed by his lover, the Krath sorceress Aleema Keto, and left stranded on Coruscant as the Krath withdrew their forces. When Qel-Droma was confronted by a team of Jedi Knights led by Master Vodo-Siosk Baas, he still refused to surrender peacefully. As a result, Master Baas and the Jedi combined their powers, and trapped him in a Wall of Light. Qel-Droma was effectively subdued, having his access to the Force temporarily removed, and unable to draw on the dark side for further assistance.
At the culmination of the Great Sith War, the combined power of thousands of Jedi was used to defeat Dark Lord of the Sith Exar Kun. They focused their power into a "wall of light" in order to subdue Kun. The attack was a success, but not without penalties; Yavin 4's landscape was annihilated in a planet-wide firestorm. Exar Kun's spirit was reduced to being trapped within the walls of his Massassi temple, left to haunt the atmosphere of Yavin IV for roughly the next four thousand years.