Items: Dalmatians 91-99, Dispel-G X4, Megalixir X3, Mythril X3, Tornado-G X3, Esuna-G, Flare-G, Float-G X3, Power Up, Khama vol. 8, Theon vol. 6, Azal vol. 3, Mava vol. 6, Salegg vol. 6, Nahara vol. 5, Mava vol. 3, Hafet vol. 4, Elixir, Mega-Potion X2, AP Up, Ultima-G, Emblem Piece X4, Orichalcum X3, Mega-Ether, Cottage X3, Holy-G, Ansem's Report 5, Fireglow
Before you start Hollow Bastion I suggest you go complete all three of the tourneys for levels, a useful Keychain (the Olympus) and for the Yellow Trinity with which you can seal the Olympus Keyhole. After you do that head back to Traverse Town for equipment and items you may need.
Anyways onto Hollow Bastion. This is the base of operations for Maleficent and there are quite a few boss battles. Anyways you'll start in the Rising Falls area. Before you begin jumping from stone to stone, jump down into the water, or rather onto it seeing as how you can walk on it. Go behind the rwo of rocks and get the chests containing dalmations. Now get back on the rock and begin to make your way up until you encounter a scene. During the scene you'll lose the Keyblade, Donald and Goofy. Afterwads, you get that wooden sword you had in the begining of the game. You will also gain a teammate, The Beast. The Beast is pretty powerful and also a smart warrior, so lets continue onward.
Beware of the Heartless as you won't be able to hurt them with the wooden sword. Continue heading upwards until you reach the castle itself. From here, activate the crystal shimmering with blue energy. This will take you to the next area you have to go to. You'll encounter some Heartless along the way, so stay back and support Beast with magic and items since you can't do any real damage. Jump into the bubble to be brought to the next area, you can take the higher one for treasure, and have Beast smash the gate down. The next area is a room full of gates. Hit switches to move until you reach a bubble, then jump into it. Have Beast handle the Heartless in this area and hit the switch then make your way back to the main area.
The large doors in the area you first teleported down here from should now be open, head for them and stock up on items for a boss battle. Once you are in the Entrance Hall a scene ensues and you get Donald, Goofy and the Keyblade back. You'll face Riku and after that you obtain the White Trinity ability.
You need to collect 4 pieces of a crest to get to the next area. There is a door to the library area in this room so head to it. In the Library you must find all the books that are in the wrong places and return them to the proper shelves. From where you start, head around the corner to pick up the red book thats on the ground. The book is Khama Vol. 8. To the right is a rwo of red books witha space in it. Place the book there and open there to open a passage. The pillar on your left has a hole in it. Examine it until the chest inside faces you so that you can open it. Inside it is an Elixir. Head up the stairs and repeat that process with the other 2 pillars. They contain a Mythril and a Mega-Potion.
Next to the save point it a desk with the book Theon vol. 6 on it. And the green trinity near the save point gets you Azal vol. 3. Past the pillar where you got the Mega-Potion is a row of orange books with one green one. Take the green book, Mava vol. 6, and insert Theon. The nearby door will now be unlocked, but before going through it, jump on top of the bookcases and grab the chest that contains a Dispel-G. Follwo the book case arouns the corner to find another pillar, which contains an AP Up.
Once that is done make your way to the second floor door and light all the candles in this area using the Fira spell. Once lighting all the candles, head over to the stone with the lighting bolt on it, and cast Thundara on it to lower the platforms that lead the the central area. Hop on them to get an Emblem Piece. Then use the Red Trinity where the mark is you'll get an Emblem piece. Smash all the vases around the statues to start a fountain which will unveil another Emblem Piece. Finally, push one of the statues over the edge. It'll fall and reveal the Emblem Piece. The Statue should be opposite the door.
Collect the pieces, heal and then place them in the door and you'll see a scene. Head through the Lift Stop to the outside, clear out all the Heartless then activate the Orange Crystal then the Blue one. Ride the trolley to the next area and fight your way up to the Great Crest area. Activate the glowing crystal nearby to raise one half of the Great Crest, now jump up it and make your way to the Chapel. Heal and prepare for a boss.
After the battle Donald receives teh Cheer Ability and you get Ansem's Report 5. Then save, for yet another boss.
Take care of her again and you'll obtain the Fireglow. An new pathway opens up beyond the Save point. Save and head down it. Save again then continue to the next boss, Riku.
After taking care of him, you obtain the Ragnarok ability. After seeing a few touching scenes, you'll be in a new "form." Head through the door into the Lift Shop. Just continue falling off ledges until you're back at the Entrance Hall, and watch another pretty nice scene... *sniff*
You'll now be in Traverse Town. Go talk to Cid behind the Accessory shop and he'll send you to the Secret Waterway. Examine the Mural at the back to recieve a N-Gummi and talk to Kairi to get the Oathkeeper Keychain. Now head to Merlin's Study and talk to the Fairy Godmother to get a new Summon. Now go back and talk to Cid and he'll install the Gummi to let you get back to Hollow Bastion, so lets do so.
Now head to the area that you fought Riku in the second time. Raid it for treasures (theres a nice Keychan here called the Oblivion) and then head through the Heart gate to face the last boss of Hollow Bastion.
Stock up on items and equipment here. And if you've yet to collect all the dalmatians, head over to the Dalmations section of the site for their locations. You might wanna try and complete all of the Tournaments at the Coliseum for levels and abilities. When you're ready, head to The End of the World.