Tsryb Fydyw Nwdz Ktkwtt Msryt Shrynyt... Repack Official

Let’s try (common in puzzles): tsryb → gfel o ? No. Let’s do systematically:

It looks like the text you provided ("tsryb fydyw nwdz ktkwtt msryt shrynyt") is likely — possibly a simple shift cipher (like Caesar cipher) or a substitution cipher. tsryb fydyw nwdz ktkwtt msryt shrynyt... REPACK

Atbash of tsryb → ghiby (not English). Caesar ROT-5: tsryb → yxwdg (nonsense). Let’s try (common in puzzles): tsryb → gfel o

A quick check shows that if you apply a (or +21 in the other direction), it may decode to something readable. tsryb fydyw nwdz ktkwtt msryt shrynyt... REPACK

So not ROT-13.