[quote=@IAmTheIsland]
[@Sadu] 

1. Where does the final confrontation w/ Ansem go down? 
2. Are we nixing the part where Ansem the Wise had his identity stolen? Therefore the Ansem here is THE Ansem?
[/quote]

I believe there was a mix-up in this part. Ansem won't be the Villain of Kingdom Hearts 1. He's still currently Diz and Alias' biological father. Though instead of his identity being stolen, it was Uther.

Uther's final confrontation will go down in Hollow Bastion after the penultimate battles in Camelot.

But to clarify Ansem the Wise, Uther(possessed), and Old Xehanort will be 3 different people.