use the question tag to ask for help 🙃

Please, say properly what the issue is. If you're suggesting that your code passes even though it shouldn't, the reason for that is you using a cheat (and one which may lead you to a ban).

However, the key should be increased by 1 with every word in a phrase.

Not a kata issue.

When you post an issue you imply that something is wrong in the kata tests. Instead you can post a question and see if somebody answer.
Maybe you shoud read https://github.com/codewars/codewars.com/wiki/Troubleshooting-your-solution.

There is no error in the tests.
Please before posting an issue look at the top of the page to see how many people passed the kata (14593 with Python); if there were errors somebody would already have seen them.
Print the input to see what happens.

Values in your variable first and second could very easily shoot beyond the range of int data type leading to overflow. As in worst case second=255*(256^3) + 255*(256^2) + 255*(256) + 255.
Try after converting these variable to long.