SCP Foundation

Some specific issues:

• Don't add a line break after your headings. The Containment Procedures and Description start on the same line as the heading.
• Don't add "-" at the start of paragraphs - it makes your article look like a list of bullet points rather than a formal clinical description.
• Think hard about the details of containment. Why is a cubical room necessary here? Why must the hallway be well-lit - should the Foundation use an air-lock instead? Why are ballistic suits relevant? Why are 5 people necessary - why not just one or two (as it seems that only one flashlight is sufficient to deter (see feeding protocol))? If bright light is potentially lethal to the entity, why is the enclosure well-lit? You need to think through all of the logistics, and come up with procedures that make sense and are relevant to the anomaly you're writing about.
• Phrases like "if at any instance", "while the other three continue with the job", "packed together", "every fiber", "vantablack gas", "if a light … is to strike its skin", "is consisted of", "which it thereafter lures" and several others, are not good clinical tone. You'll need to work hard on precision in word choice and syntax to match the tone expected by the site - that will come with reading good SCP articles, and getting feedback on specific phrasings.
• Check your spelling. "it's escape" should be "its escape", "
• Don't include anything imprecise. You suggest that gas can only be restrained (how?) by bright light (how bright?), refer to a light bright enough to penetrate the gas (how bright?), the strength of the gas (do you mean density or something else?) - all of these should be make as scientifically precise as possible to maintain the Foundation's aura of professionalism. Similarly, you mention that this is the last of its species - how does the Foundation know that? Any statements in the Description should be able to be supported by evidence (you don't have to include the evidence, but a general statement like that one suggests that the Foundation should explain why it knows this).
• Your experiment log is insufficiently interesting. You simply have the creature attack a scientist, without creating strong action or character. Nothing surprising happens, so the reader loses interest. Also, why would the Foundation use a scientist to get this sample from a dangerous creature when it could get a D-Class to do so? And why didn't the torches stop the creature from attacking? And why was it so cold?
• There's no need to redact so much - it's distracting. You can use explicit language - the Foundation is not squeamish about that. Only expunge data (and really, only use blackboxes) when it's useful for the story and justified in-universe.