Reserved
This one took some effort to solve.
It uses Ceasar cipher. This tool was useful to quickly decode the message.
Something that threw me off a bit. Big hint below, spoiler obviously.
The word REALIZE is important here, but not as-is. Decipher the text block, then use the now-ciphered string when solving for the answer. Using REALIZE on its own doesn't seem to lead anywhere.
For each time the SCP speaks, it's a Caesar cipher, as previously stated. As SCP-2122 says in its last statement, you need to see which letter replaces or would replace "a" in every block. For each letter, you need to use that letter as the Caesar key to each corresponding letter in the ciphered "REALIZE" block (for example, "o" is the replacement for "a" in the message, so you would use the key:
abcdefghijklmnopqrstuvwxyz
opqrstuvwxyzabcdefghijklmn
to decode the first letter.)
Repeat this for each corresponding letter, and you eventually get "syncope" as the answer.
Hopefully, this explanation made sense. I'm not too good at explaining puzzles like this.
Great one (second puzzle solved for me). I had fun creating a C program to help me (I'm weird).
I also spent a bit more time on it than necessary since I thought it was a random substitution instead of a shift, and it took me a while to realise this.
I also had to fumble a bit to find the various values of shift (I'm pretty sure there is a mathematical relationship between all of them).
The 4th answer was also a bit tough.
You all are such excellent scientists, and I love how you never stop digging.
… oh crap.
(Nice work putting the first hint that this thing WANTS to be solved in the interview log, so that I only saw it after I'd been nerd-sniped several times already. And the worst part is, I know I'm not going to stop trying to solve it…)