The Oblivion keyblade is perhaps the most distinguished keyblade in all of the “Kingdom Hearts” series. Its build is similar to the Kingdom Key (the default keyblade) but it is all black with scroll designs coming off the edges and is very long. Obtaining it in Kingdom Hearts Recoded, if you go to the right area, is not all that difficult.
Progress through the main story, fighting bosses and heartless, until Sora comes to Hollow Bastion and his keyblade goes missing. Hit the two switches to make it into castle at Hollow Bastion, and then press “A” whenever the Heartless come near you to make Goofy and Donald attack them, as they are the only ones who can damage the Heartless at this point.
After getting through the dungeon, and recovering Sora’s keyblade, you will first fight Pete. Like in previous Kingdom Heart games, Pete is of medium difficulty. He can inflict the silence effect, which keeps your characters from using magic, and can summon Damage Blocks to helps him.
Despite these troubles, all you really have to do is circle Pete and smash him with your keyblade until he is defeated. Just keep your guard up, because he can inflict damage when circling him. Just try to stay close to his back, and you should avoid most of the damage. Here’s where it gets harder.
Pete summons Riku to battle you. The first round is easy, but after this Riku begins using a diving attack that is powerful and hard to block, and then he warps around the stage, making it hard to hit him and hard to defend yourself.
Keep running side to side to avoid him as best you can, and attack Riku whenever the chance presents itself. After his health is depleted, Riku will be defeated, and this section of the Hollow Bastion dungeon will be finished.
With Riku defeated, Sora can now claim the Oblivion keyblade which, depending on your play style, is the second best keyblade in the game. This is if you primarily use the keyblade during your battles. If magic is your option, then Oblivion is unfortunately rather useless, but still looks cool.