a bit too late for that now, with dozens of languages and thousands of completions

Done :)

Random tests have actual and expected flipped, could you fix it?

The sample test currently checks against 243.33000000000001d, not 243.33m.

Though I agree the description is somewhat brief, I think the application of some common sense is suffice to solve this Kata. The task is pretty obvious.

Fantastic Kata! Taught me about C#'s feature to have implicit operators. Really satisfying once you solve it.

However, it should be stated more clearly exactly what order of operation is expected. The only clue is that the test method is called "bedmas", but it's nowhere to be seen in the description.
Random tests would be a nice addition as well.

There are even 3kyu katas much easier than this...

I think it's silly that the shift gets changed every character.

In my humble opinion, it would make much more sense if it got changed every letter, which is how you would do it if you were to use this cypher in real life.

Side note: the latter is also how I initially implemented it, because I assumed this was how you were supposed to do it.

Best Practises? Really?

C# translation here. Please review and approve.

Top right: View profile -> Kata -> Unfinished

You can't. However, users automatically become allies if they have the same clan tag, or if they invite each other.

I think 5 kyu is fine.

No clue what you did there, but I like it

It was downranked.