If Lightning is Sin, and Sin is Jecht, then that must mean that Lightning is Jecht.
Accordingly, Tidus had two mums. Which means FFX was actually a really progressive story when it comes to gender and sexuality.

Except... Jecht/Lightning was a violent drunk and a terrible parent, so FFX was actually portraying same-sex parents in a seriously negative light.

Now I'm just confusing myself. Zidane is secretly Ultimecia, right?