In Kingdom Hearts 358/2 days what is the ultimate weapon of Roxas?

his best weapon is either Oathkeeper and Oblivion (yes it is one item) or Two Become One. Oathkeeper and Oblivion are when you get the zero gear and put three ability units into it and Two Become One is two ability units and any other two units. Oathkeeper and Oblivion are fast but have less strength than Two Become One and yes i think it is the best NDS game of the year