It's called a Caesar cipher. That will make it a lot easier for you to search for all the kata this is a duplicate of.

• Input validation is a worthless requirement and should be removed
• There're already several katas about generating random data, so it's a duplicate

The previous kata was quickly retired, surely you don't think an exactly same thing will survive for long?

Still same issues:

• multiple return types (please drop useless input checking, or at least use exceptions)
• randomness check doesn't work (simple counters pass tests)

1. Issue about multiple return types, mentioned by @mauro-1, is not fixed. The function still expects multiple data types as a result (bool/list[int]).

2. Test for randomness is invalid. You expect that output with 1000 dices must contain all values 1-6. In this case, the following outcomes (non random) will pass the test:

1,2,3,4,5,6,1,1,1,1,1,1,1,1,1,1,1,1...1
1,2,3,4,5,6,1,2,3,4,5,6,1,2,3,4,5,6...

Example of wrong uploaded solution: https://www.codewars.com/kata/reviews/604e9ba8c33f340001066011/groups/604f0347c33f34000106650d

Read about randomness tests on Wikipedia: https://en.wikipedia.org/wiki/Randomness_test