No. 4: Regulus (Nereid) – Tales of Destiny 2/Tales of Eternia

There’s nothing quite like fighting a hidden boss that happens to be a possessed historical figure. The namesake of the Regulus Dojo and the Regulus gnoll is available for a fight in Tales of Destiny’s hidden dungeon. What makes the battle tougher is the fact that he’s possessed by the game’s main villain and is capable of countering everything you throw at him. The early games in the Tales series featured battles on a 2D plane in real-time, kind of like Street Fighter. Now imagine having to micro-manage four different characters with their own move sets, spells, tactics, and items. This boss fight almost required you to pause after every action to queue up another command. But if you did manage to defeat him, then you could take pleasure in knowing you killed the hardest boss in the game.