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.
- HP: 1050
- EXP: 16000
As usual boss battles have been recently, it's best to take cautious measures by casting Aerora and summoning Tinker Bell. The only way to defeat Behemoth is by attacking its horn. Try to get on its back, as this seems to be the safest strategy here. The Behemoth has two major attacks; one is recognizable by glowing horns. This one isn't easily avoidable, so try to Dodge Roll under the Behemoth or around the area to try to avoid it. The Behemoth seems to bring a large black sphere into the battle, and your cue for dodging will come when the large ball of energy splits into smaller ones that chase you around. The other major attack it uses involves Thunder, and it could easily hit you if you don't stop yourself in-between combos. Otherwise, the attacks don't seem to be too critical so as long as you have all the right spells (Cura, Aerora, Summon) and a large amount of MP, it's possible to go all out on the Behemoth to try to finish it off quickly. Defeating the Behemoth will give you the Omega Arts accessory.
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.