Per 
A photo from "The backrooms" taken by scp-5820.
Item #: SCP-5820
object class: Euclid
special containment Procedures: SCP-5820 is to be contain in a 12x12x12 room and can be treaten by Level-2 personel. Staff aren't able to give any weapon to scp-5820 except for a test with at least 2 guard with high level. Staff aren't allowed to put SCP-5820 into RELM state more than once a week except for a test with every necessary precaution.
Description: SCP 5820 is a normal male of 170.7 cm height that carry a mask made out of yellow wall paper covering most of his face. This scp is the only survivor from a dimension called "The Backrooms" that has not been indentify by the fondation yet for specific reason. 5820 is really strong for a human being, know how to defend himself and only need the minimum of what a human need to eat.
Before being trapped in the dimension it was called Richard Millegnium, a simple man who worked as a data miner in a office. The last time he was seen before is disappearance was in his own house. one month later, he was seen one the subway Madeleine at Paris completly naked with blood on both of his hands, a mask covering his face and a bagpack with a camera, a flashlight and human meat. In panic, he begin to killed anyone he see in the subway and twelve life were taken before being putted down on fire by authorities. He did not die from the four bullets it has taken during the fight and recovered quickly. When he started to tell his history in the dimension, he taken the curiosity of the fondation and was immediately being taken to the site-██ where he could tell everything he saw.
SCP-5820 was apparently taken to a dimension that as been heard multiple time by the fondation but never confirmed. this dimension is almost infinite and seems that the time work differently than normal due to SCP-5820 disappearance being of one month but is saying that it was stuck in the dimension for more that thirteen years. His body look like a 30 years old wich the age correspond to his disparition but a DNA test has been made and the results were saying that he is more than 60 years old. 5820 say that he survived 30 years by killing and eating others that were trap with him.
5820-A is a old yellow mask covering the face of SCP-5820, it is appenrently made out of the walls from the "Backrooms" dimension. 5820-A was found by SCP-5820 when it was trap in the dimension, this mask is the only precious thing in the eyes of 5820, he say that he take this mask for some sort of trophie to prove that he is a survivor from " The Backrooms". When putting off the mask out of 5820, a stange reaction happen, he begin to scream and saying name of person that were missing years ago. The reaction of 5820 has been called: 5820-RELM state. Many personals think that the names it scream are victims of the dimension. While in the RELM state, the mask has been tested and it has nothing to do with anything surnatural, the mask is simply made out of old yellow wall paper. When putting the mask back on SCP-5820, it get back to normal, he doesn't remember anything he did while screaming and when asking him the names, doesn't seem to know anything about it. 5820 do not enjoy Being in the RELM state, it even threat and try to kill multiple personel if they put out the mask multiple time a week.
After giving everything he know about this place, SCP-5820 was still considered civilan, so the personel administred him amnestics to be reintroduced to his community, but anmestics are reveal to have none effect on it. After several test about the immunity of every amnestics, it was decided by the fondation to put Richard Millegnium contained and rename him SCP-5820.
SCP-5820 is a survivor, he as a big fighting knowledge, it knows how to fight unarmed and can fight with guns, knifes and most weapon. It is analysed to be more efficient in combat than a MTF-Epileson-11. his strenght was being tested once with 8 Class-D personel. The class-D were asked to try fighting with 5820 without killing it with weapons like : american fist, a baseball bat, etc. The test finished with 7 class-D killed by 5820, the last one survived by putting out the mask, provocking the RELM state. After the test, 5820 asked if it could eat the class-D he had killed.
The backrooms :
The backrooms is a dimension with infinite space. The dimension suspected to be a cause of many numbers of disparition by random people all over the world, especially the one name when scp-5820 enter the RELM state. All of the following information is from scp-5820.
The dimension has 3 different level that are being acces by simply traveiling in the backrooms for a long time.
—Level-00 :
a place that look like a normal backroom with yellow old walls, a rusty carpet and fluorecent light that make a hum-buzz sounds. The place seem designed to lose sanity with walls placement being in the way to make think that you are lost in this place. There are no nearby source of food, the only way to be feed is to eats others survivor trap in this place. Imaginary friends can be created by a survivor mind while staying too long in the dimension, it was the case with SCP-5820. It is in this level that SCP-5820 found 5820-A and decided to keep it. Scp-5820 stayed 15 years trough this level.
—Level-01 :
the next level is being acces by some stairs found in level-00, the stairs lead to Level-01. the level is relatively similar to level-00 but the walls look more old and shattered and the celling lights are making less light and can stop working at any time, especially when a survivor walk in a room. This stage is also filled with humanoid creatures called "The lonely crawler", this creature will make a non-human scream in the area around him, he will attack and kill every survivor he see. if a non-human yell is heard in the level-01 it is recommended to walk in the opposite direction of the scream. Scp-5820 stayed 10 years in this level.
photo taken by scp-5820 while he was in Level-02 of "The backrooms"
—Level-02
Nothing like the others levels, this level is full of long corridors filled with pipes all around the place, multiples sound is heard, coming from every corner of the level. Drops of water, metallic shattering or even non-human scream is heard troughthout the level. there is no more "Lonely crawler" in this level, but there is another creature far more dangerous. "The hidden shape" is an humanoid creature who look like a shadow and will run at the survivor and kill every surivor it found. the only way to surviv while being close to "The hidden shape" is to run until you reach a different corridor. The corridors with these creatures are localized by corridors with blood on floor or human scream. Scp-5820 stayed 5 years in level-02.
—Final
At the end of the Level-02, the corridor will simply end on a brick wall. Scp-5820 simply punched the wall with his fists,even though his hands were covered in bloods he continued until the wall break down. after the break of the wall, he say there was a bright light and he woke up in the subway.
"The backrooms" hasn't be place as an scp because there isn't enough proof that this place exist beyond scp-5820, the other reason is : there are no way to contain this dimension by any mean because the entire victims of this place are random and there is no other ways to enter it. If the fondation found the source or even some sort of entrance, "The backrooms" will immediatly be contain and put under surveillance in one of the site or even create one site especially for it, but for now, the only piece of evidence is Scp-5820. If any other surivor from the dimension is found, the survivor will be put into containment as Scp-5820-1.
