Kingdom Hearts/Hollow Bastion (2nd Visit)

When you arrive at Hollow Bastion, make sure you go to the Library. Here you'll see Beast and Belle happily reunited. Talking to Belle will make her give you a new Keyblade, the Divine Rose. Go to the passage leading to the Lift Stop behind the Save Point and take the lift. Go to the Castle Chapel (where you defeated Maleficent) where you'll see the newly-rescued Princesses of Heart. Talk to them before going through the Lift Stop to get to the Grand Hall. After battling the Heartless that appear, run up the stairs to the top level to find a chest that contains the Oblivion key chain. Head through the giant Keyhole if you're prepared for another boss.

After the battle, go back to the Library and head to the bottom floor to find Aerith. You'll get Ansem's Reports 2, 4, 6, 8, and 10. Talking to her a couple more times will have her upgrade your Cura spell to Curaga. You can now leave Hollow Bastion to face the final boss at The End of the World.