Egregore

Egregore is a strange fungus-like life form that is commonly associated with the Darkness. It is commonly seen on various locations like the Derelict, the Cabal Carrier Glykon Volatus, and the Leviathan.

Overview
Egregore is highly similar to many other fungi species on Earth in how they grow and live, but it does not spread its soil but rather between dimensions of space like ethereal conduits, similar to the Ley Lines in the Dreaming City. Most notably, how they feed on death. While Earth fungi feed on dead or decomposing matter, Egregore is drawn to the unique psychological phenomenon that comes from the deaths of sentient beings. The fungus appears to suspend a victim’s mind in the suspension of the death of cognition, akin to falling into a singularity, where it feeds on the victim’s slow death. Ordinarily, it would take centuries for Egregore to spread across a planet or a ship the size of the Leviathan.

Egregore spores are linked to a mycelial network that connects them across the void of space and even alternate dimensions. These spores can apparently "open one's mind" to the Darkness, as well as those consumed by the fungus, and permit affected individuals to pass through energy barriers generated by the fungus.

Via the Crown of Sorrow, Egregore was able to spread through it whenever it is used following its change in use following the experiments aboard the Glykon. This can be seen aboard the aforementioned Cabal ship and, most recently, on the H.E.L.M..

Egregore can also link to other Darkness-infused structures, such as the Pyramids and those it has infected, and connects them to a central point that communicates with those like Rhulk and Calus.

Trivia

 * Egregore refers to a concept in Occultism wherein an expressly believed thought manifests amongst a group of like-minded thinkers. The definition of this has changed over time, from manifesting an actual physical being that assists the group, in the form of a guardian angel or other being, to just the ability for the thought to grow in strength within the group, becoming evermore influential in the groups actions. Therefore, egregore is parasitic in its relationship to its host group. This can be said to be represented in Destiny, as Egregore have so far appeared to grow within regions of lifeforms with a strong like-minded thought process and purpose; Loyalists and their dedication to Calus, Scorn and their dedication to finding meaning to their existence. Drifter's ownership of some egregore may indicate his singular strength of will to survive, with the Egregore feeding on this.
 * Egregore is linked to the common theme of memory from other Darkness-based creations, such as the Nightmares and Taken.

List of appearances

 * Destiny 2
 * Season of the Drifter
 * Season of the Chosen
 * Season of the Haunted