Sin's Overdrive *Spoilers*

I'm on the 4th version of Sin, where he's hovering over the city and you're fighting him head on. I keep getting all the way to about 25000 and then he uses his overdrive and it kills me. I tried once using my aeon to take the hit, but it killed me that way, too. It wont just kill my aeon, it kills all my people, too. Shouldnt it just kill my aeon? Or, am I just really confused, is he swallowing us? It says he's using some Gravija move thing, not swallow or anything like that. Is my game just messed up, or did that happen to you guys, too?

Giga Graviton results in a Game Over, no matter what. It's similar to FFX-2, if you allow Vegnagun to fire on Spira (although that elicits the Bad Ending). Just beat Sin before it can use GG.