Completing the solo stories will unlock more, but more importantly, beating each of the final missions offers 200 gems, while some stories offer weak structure decks of that archetype
The Amber and Amethyst deck is probably the easiest to master, while the Ruby and Emerald deck is the trickiest of the three to understand, although its probably the most flexible and adaptable of the three decks
Korean and Chinese cards also print their own codes rather than the English shapes, so the same rule holds: match the code to its own system, not to the English name
Monsters don't mesh subtly
Perhaps this is not the most competitive of the decks but is a full 10/10 in terms of thematic
Forbidden Memories" as he is the final opponent in his tournament as does he he also serve as the final boss for the modern era of the game as well