Ok, just think about it for a while! It all fits perfectly. 'cus you see, Aeris has dark hair, and Ultimecia has dark hair. And I bet Aeris had Squall's ring at some point too, BUT SHE NEVER RETURNED IT! Hah, there's proof.

Oh and if you play the opening sequence backwards, you get this message spelled:

cesoniv socew cesul sohtif
cesoniv socew cesul sohtif

iem irebil ,onmos e sov etaticxe
.tnus non eanuc
ilataf irebil ,onmos e sov etaticxe
.tae non sunmos

Ok, I don't know what this means yet, but it's got to mean something.