Let's take a look at this:
SCP-1903-1 is to be kept inside a 5 meter by 5 meter containment cell.
Apparently, this is a two-dimensional universe! Flatland, anyone? You make the same mistake later:
The cell is to be situated at the center of another cell of 10 meters by 10 meters.
Okay, so it's a cell within a cell? Odd, but there must be some practical purpose for it.
Initial capture of SCP-1903 was achieved when the then current host SCP-1903 arrived at the outside gate of the [DATA EXPUNGED]. He asked to be arrested, and was taken into custody. Upon being placed in a holding cell, the host closed his eyes for the prerequisite time and activated the effect. Due to the nature of the effect, the state of the cell in which the host was confined, and a simultaneous activation of SCP-███, a containment breach of both SCP-1903 and SCP-███ were only very nearly averted in time. During the days prior to this incident, [DATA EXPUNGED] was monitored using the term "The Darkness" numerous times in communication.
Okay… several problems.
1) Arrested implies that he was arrested by civilian forces, but the [DATA EXPUNGED] and containment breach implies Foundation involvement. The Foundation does not arrest anyone. They Secure and Contain. How does he know about the Foundation in the first place, if it's the latter case?
2)Why even the need to mention SCP-XXX?
3) If he was detected before, why did the Foundation do nothing about it?
SCP-1903 is an infectious anomalous effect which occupies one host at a time; SCP-1903-1. The anomalous effect takes place whenever the host closes his/her eyes for longer than 2 minutes and 7 seconds, or at 2116 local time, and lasts until 0654(regardless of activation time). Local time is always respected with regards to the times of activation and ending. Moving the host over timezone lines during an event will simply result in the effect ending at 0654 in the new local time.
"Infectious anomalous effect". Is it viral? Memetic? Hallucinatory? Cognito-hazardous? If it's just "anomalous", that's not a very good description.
The subject must be contained inside a room with 4 walls, a floor and a ceiling in order for the anomalous effect to be observed. Testing has indicated that when the room's ceiling is opened to the outside, the effect will no longer activate.
Okay… then why not just have his enclosure like 10 meters tall, outside, with an open ceiling and perfectly smooth walls? It would be miserable for him, but hell. If it's in the name of containment, the Foundation will do it.
Given the escape attempts by █ of the past hosts(see IR-1903-B), this is unfortunately no longer a valid containment procedure.
…okay then, seems a bit of a cop-out… but then, you could not give him any materials to escape with. Like, don't put anything in his cell that could be potentially be used in escape attempts.
The effect of the anomalous event on SCP-1903-1 is two fold. First, the host loses consciousness. Second, the host dreams for the entire period, from activation until 0654 local time. EKG monitoring of the heart is sufficient to determine this without risk.
…I'm not entirely sure EKG can do that. EEG, yes. But can EKG detect REM sleep?
Common environments encountered include halls of fire, tar pits, and boats made entirely of flesh and bone. The host is subjected to torture in all environments, the form of which is dictated by whatever the host feels is most gruesome. It has been shown that introducing a host verbally to a new form of torture that is subjectively worse than that previously described will result in encountering that form during the next event.
Generic visions of Hell.
Monitoring equipment will extend the effect to any rooms currently viewing the host if the effect triggers while they are activated. Due to incident 1903-C which included the loss of ██ personnel, all monitoring equipment is to have automatic shut offs installed set to trigger at 2115 local time.
Okay… but what if the effect is accidentally activated before 2115 local time? Nitpicking, I know, but still.
From what I can understand, you have an infectious thing what makes stuff dark and what gives people bad dreams and what kills people. It seems pretty generic and, quite frankly, isn't all that interesting.
Also, if it absorbs all non-solar light… how can we see the subject's face in the picture?! Why is there even a picture at all?!