Per 
SCP 5955
Containment Class: Euclid
Description:
SCP 5955 is an exterritorial entity of unknown origin. It is a noncorporeal entity that appears as a large black mass with numerous tentacles that secrete a black viscous substance. The entity will cause a state of depression by tormenting the subject.
SCP 5955 can access the possessed humans’ memories and can cause states of severe depression, often leading to suicide if not contained.
Containment:
One class D personnel is recommended for containment procedure. In a concrete cell the class D personnel is to have a reflective surface, then the class D personnel will create a triangular symbol on the reflective surface.
After drawing this symbol and chanting the words LORF!
SCP 5955 will inhabit the reflective surface and be unable to escape. This will cause severe depression and psychosis in the Class D personnel unless the reflective surface is shattered, by which 5955 can no longer be contained.
Addendum:
An occultist cabal known as [redacted] began invoking SCP 5955 in 2012 under the name Black Trigag. Ritual Text cited by [redacted]:
“Understand! You cannot reach the gate if you do not know yourself. You shall be struck down. Your mind will be obliterated by your very actions, you will fall, a skeletal reminder of those who would not face the within. Your soul will be but a ruin, those hidden things that brought you terror and anguish will become your only truth and self. I guard the abyss. I know your soul, I know you, I know all, I see all, I am all. You cannot hide from yourself. The abyss is hungry, come on in.”
As of 2012 the sightings of SCP 5955 have increased as well as levels of depression linked to its existence. Followers of 5955 believe it to be a form of catharsis to summon 5955 by painting its sigil on a reflective surface and then shattering the surface once they sufficiently faced their own perceived character flaws or misgivings.
SCP 5955 is then free to prey on unsuspecting humans until it is captured and contained by D class personnel.
