Canvas in the castle has 5 suspects and 3 clues
Now you must investigate each of the suspects first and then you will move on to the second part of the quests: finding clues.
Here are the 3 clues and their locations:
Then, you have enough clues to accuse someone
You need to have addon
Xemnes decided to appoint Marluxia the head of Castle Oblivion when Saix informed him of Marluxia's plan to overthrow the Organization. Saix was unsure of most of the Organization members' intentions and decided to send them off to Castle Oblivion.
just get battlehorn add on
It's impossible to get to Castle Oblivion in KH2, but it does appear in a flashback during the beginning of the game while you play as Roxas.
Castle Oblivion originated in Kingdom Hearts Birth by Sleep after Ventus feel into a comatose state. Aqua created Casltle Oblivion to have a place to keep Ventus safe. Castle Oblivion is also used as a headquarters for Organization XIII. In Chain of Memories, Sora, Donald, Goofy, and Jiminy Cricket search the Castle hoping to find Riku and the King, but end up losing their memories and having to fight the Organization instead. They are then contained in sleeping capsules in the castle until their memories return.
You're most likely referring to the Oblivion Keyblade, which is given to you by Riku (shortly before entering the castle at The World That Never Was).
my friend beat the game and he said "you fight roxas or something."
Kill a monster and get it from it
No
The Olympus Coliseum is a world that is eventually unlocked through progression of the storyline. In Kingdom Hearts, it is located in between Traverse Town and Deep Jungle. In Kingdom Hearts II, Olympus Coliseum is located right next to the Land of Dragons.
In Chain of Memories, the trio only go through Castle Oblivion and that big grass field in the beginning of the game when they are looking for King Mickey and Riku.
look for a oblivion gate and kill deadra that is how you get the hearts you can clone them