"V sbyybjrq gur ehyrf"
I don't really have much experience with codebreaking, but I was playing a Pokémon Mystery Dungeon romhack called MysteryMail 6: Agents of Chaos, and on the Exploration Branch scene 8, the following code appeared. Apparently it is solvable by itself but I have not really touched ciphers before.
The cipher reads as follows:
Ckwyoyjyq'g rteza.
Sndi?
Pr'eu zeb bzbpwenm jz wi cxgs.
SISK? Fli men?
Gsuuw te.
Bbsr, prq yzmd't vzuyztu da zcx nr gnmyvhe? Otslyk Uqwtvow Jyyslblb Qcdrvprkk?
Aprpe qanz.
Sb. If cn.
Fdi.
Vxh. Zbrv fmx. Xjmkyb CAEOO zdpu gjia zwqns ddhx uxxcqhku, gkbki?
Xq fjhl sj dhcdp.
My best guess for clues in the cipher is that the phrase CAEOO means DECOI and SISK means IKEA but those are just my best guesses. I tried the Vigenére cipher but I don't think it works. Also, if you do figure out the solution, can you explain your chain of thought for how you figured it out? I want to learn how to potentially solve ciphers by myself.
(The hack can be found at https://hacks.skytemple.org/h/mm_agentsofchaos )
Edit: Someone who has already solved it apparently said the following line:
(it's sorta a combination of certain existing ciphers, but he did some things that i don't think have ever been done before)
If someone can confirm that there isn't enough information for this cipher to be solved, please let me know. Apparently you need at least a paragraph or something.
Edit 2: The cipher's name is apparently HandBrain 3.0. That recontextualizes what the miscallaneous Italicized words mean, and that apparently you were supposed to do HandBrain 2.0 to do it realistically? I'm going to ask where the heck that puzzle is.
Edit 3: The creator said:
The first bits are easiest of H 3.0
The rest is. A lot more complex
Vagueposting spoiler: As the flywheel turns...
Also apparently Handbrain 1.0 and 2.0 were just drafts that the creator made in some CS class finals, which absolutely do not help. I'm going to read up on cipher literature and see if that helps.
Edit 4: I found Handbrain 1.0 and 2.0. Handbrain 1.0 was a simple substitution cipher with key of LYRXACVBHNMJIUQKOSZDGTPEFW but I couldn't figure out Handbrain 2.0. (Handbrain 2.0 is like an easier version they gave me for sympathy because I have been working on this for like forever)
(This is Handbrain 2.0)
Handbrain: Hdgo pzcd. Puhgyi?
Handbrain: Hmy zhgvtjgli ah pyd kcyffldswd j8 Bfwpvf!
Zelulo (reply to 1st): Pjnz wzgdhi! :)
Handbrain: Mlsj, zmlx. Kijkql pm kuvizyy, jiwzhku exnc gxlcxmldqma.
Edit 5: I was given some help from the creator. Apparently this cipher was meant to be solved only by another specific person in MysteryMail, and those two people have just been trading techniques for... a while. That specific person it is for was the one who told me that the puzzle was apparently solvable by itself.
Also apparently Handbrain 2.0's name relates to the name of a Pokemon in some way and is a cipher found on dcode.fr . The creator revealed this information because I was stuck for at least a dozen hours and they wanted to ease my suffering slightly. My guess is Porta (Similar to Ponyta).