Costume Kingdom

You'll earn this trophy when you've completed the game. You'll also get the Stratus Costume/Hallowmon when you. If you're missing any trophies when you've earned this one, hit "Play/Continue" on the main menu and it'll pop you back into the open world, allowing you to collect/complete anything you might still be missing. If you're having any trouble with the game, the fights, the Champions or even the Quests, below is a full Platinum walkthrough video for you to use/reference as needed: