I never understood, what order did Aqua and Ven's final battles take place in?

 

I mean, does after Ventus and Vanitas merge, which order do the battles after that take place? (Not counting the Final Episode)

 

Does the fight with Ven and Vanitas inside Ven take place before Aqua fights Ven/Vanitas?

 

Does the fight with Aqua and Ven/Vanitas take place before Ven's battle inside himself?

 

Or do both of the fights occur at the same time, so that Ven and Vanitas fight inside Ven, while Vanitas also controls Ven and fights Aqua?

 

I always thought they took place at the same time, but i don't know.

No idea. I'll figure it out in about a year.

Aqua's fight against Ventus-Vanitas occurs before Ventus's battle with Vanitas.  When you fight Vanitas (in Ventus's final battle) the X-Blade is partially broken, which happened during Aqua's battle with Ventus-Vanitas.

they happen at the same time while ventus is battling vanitas he is controlling ven and making him fight aqua,

its never been confirmed as far as i know but i'm fairly sure thats it

Probably at the same time. 

Never confirmed. There are a number of possible answers.