The use of keys as weapons / Item Crashes, followed by a question mark from your character. Doubles as a Moment Of Awesome if you manage to defeat Dracula ONLY using it as described above.
Maria's ending is far more cutesy, and serves as a hilarious Mood Whiplash compared to the rest of the game.
If you tried to play the original version of the game with the wrong system card, it wouldn't just display a boring error message like most game, but rather load up an entire joke minigame called Akumajyo Dracula Peke. It must be seen to be believed.