vegeta SSJ4

Yea, you don't need to do anything in that lift stop. You must find the last book which is lying on the table next to the save point and looks orange and then put it in the book case on the opposite side. This will unlock a door that leads you to a floor above where you fought Riku. You now have to gather 4 emblems that you have to place in the door at the first floor. I don't quite remember how to get those, but check the guide antime you're stuck ;)