I assume the two versions look something like these two:
When the original set came out it did not have the "fate" mechanism yet. Even though Kythis was a promo with the expansion that had the mechanism it looks like it was printed before they formalized it (my copy doesn't have the fate mechanism either and I got it when it first came out).
As far as I can tell they are functionally the same. The wording was changed slightly but seems to have the same impact.