If you want the absolute maximum card count, make sure you have Yugi the Destiny and Kaiba the Revenge installed on your system. Joey the Passion will automatically import those card sets, giving you the ultimate PC dueling experience.
Once you have the full library at your disposal, you can move past Joey’s basic "Red-Eyes" strategies and build meta-defining decks: yugioh power of chaos joey the passion all cards hot
Some third-party tools allow you to toggle an "Unlock All" switch while the game is running. If you want the absolute maximum card count,