Okay, took a quick look at this since it fell to page 3 with no replies.
Writing-wise, needs a fair bit of work. The containment procedures are excessively specific (why does the "room" need to be an exact cube, measuring taller than a 3-story building? At that point you have a warehouse and not a room) and almost nonsensical, but at the same time not complicated or difficult in implication enough to merit a Keter class. You have run-on sentences like "Should the containment chamber/room lose structural integrity, or should SCP-XXXX escape or leave the room, all personnel are to evacuate, into a blast-proof chamber, or bunker, and qualified personnel should immediately disarm, or destroy SCP-XXXX, and return it to its chamber." that make it difficult to process the text (maybe read this page for some examples of how to address this: http://www.scp-wiki.net/clinical-vs-complex) and also are on the overly vague side anyway. Also, if someone destroys the entity, how can it be returned to containment? And also a lot of simple errors like mixing up "it's" and "its".
Conceptually, this feels like a slimmed-down version of SCP-1850 (which is a plane that behaves like a bird) with a bunch of dangerous attributes added for… no particular reason, it seems like. I personally would downvote immediately for shoehorned in violence like:
This has resulted in ███ Foundation personnel fatalities, resulting from containment chamber breaches, and the viewing glass being penetrated from the rapid discharge of SCP-XXXX's Hellfire model missles.
Not only is it never mentioned that the containment chamber needs to have a viewing glass to begin with, the fact that the Foundation has lost over a hundred people to this thing just makes them seem incredibly incompetent, especially with how simple/vague the containment procedures are. The violence feels gratuitous. SCPs don't need to be dangerous to be successful.
I personally recommend trying something else. If you really want to try to make this work, definitely get the base idea polished up in the Ideas and Brainstorming forum before you try fixing the draft. Go to that forum, post a quick summary of the concept you want to write up (don't link the draft unless someone asks), and reviewers there can help you make the idea more workable.
