Instead of Vash in the cage/jail in the detention center, it is a twilek jedi, her apprentice. After killing the Revan vision and exiting the tomb, it gives you a chance to talk to Master Vash. Same stuff as the other masters(how to ends force bonds, where is everybody...) Sion walks in to the room, Vash force pushes you out the door and shuts it, Vash and Sion duel(not shown). If DS, I assume you can kill her, i havent tried it yet.
Edit: Just installed it yesterday,works great. Cant beven tell its a mod. Seamless voiceovers, perfect lypsynch, correct animations.
Oh Yeah, outside the vision tomb a Sith Assasin is using her lightsaber and drops a datapad explaining what happened and why she is in the tomb.