- 1). Add 3 Rainbow Dark Dragon cards to your Yu-Gi-Oh deck. This is the central card that a Rainbow Dark Dragon deck is built around.
- 2). Add 2 Demise, King of Armageddon cards to your deck. This is not required, but very useful. Summoning Demise, King of Armageddon allows you to pay 2000 life to destroy every card in play. This leaves your opponent defenseless to the Rainbow Dark Dragon's attack.
- 3). Add Dark-type monsters to your deck until you have 20 total monsters in your deck, counting the ones already added to your deck. You need to have at least 7 unique monsters in your deck to summon the Rainbow Dark Dragon. It is better to have 10-12 different Dark-type monsters for the Rainbow Dark Dragon deck. You can use almost any Dark-type monster for this because the main purpose of these monsters is to be placed in the graveyard or defend you while you wait to summon the Rainbow Dark Dragon.
- 4). Add 1-3 End of the World cards to your deck. You must use this card to summon Demise, King of Armageddon. You do not need any if you do not have this monster in your deck. Include only one if you just want the option to do so. Include two or three if Demise, King of Armageddon is going to be the main way for you to clear the enemy monsters from the field.
- 5). Add 3 Veil of Darkness cards to your deck. This is optional, but useful for this deck. This spell will permanently give you the option of placing a Dark-type monster you draw into the graveyard and drawing another card. This is a good method of getting monsters into your graveyard.
- 6). Add spell and trap cards to your deck until you have a total of 40 cards in your deck. Remember to include cards to summon monsters if any of the ones you select require a spell to be summoned. For example, you need End of the World to summon Demise, King of Armageddon. Your trap cards should focus on stopping enemy attacks and destroying monsters, but there is a large selection of traps that work well for this deck.