I know that there already is an answer to this question, however after taking some tests on Showdown I found out that it is, in fact the last user of redirection that becomes the center of attention. So if Togekiss uses Follow Me first, and then Amoonguss uses Rage Powder, it's Amoonguss that becomes the center of attention, not Togekiss.
Here are the tests:
>- Test 1, where both Pokemon faint at the hands of the opponent. So we find out that the first attack goes towards Amoonguss and not Togekiss, and after Amoonguss faints Togekiss is attacked.
>- Test 2, pretty much the same scenario as the previous one. But here Amoonguss lives the first blow. We find out that the second blow, instead of going onto Togekiss, hits Amoonguss. This means Amoonguss was, in fact, the center of attention.
>- Test 3, where it's Togekiss that is the slower redirection user. In this, the situation of Test 2 is just reversed. Togekiss takes the first blow, meaning we can assume that it was the center of attention.
Inferance: It is the slower redirection user that gets to be the center of attention.
Hope I helped!