Card shop
After you are done in Clock Tower you can reach the card shop. To get more Domino, increase duelist level and deck capacity duel Bonz ten times. Keep ante-ing to get more cards. After ten duels, sell the cards you do not need and you will get a lot of Domino. As you keep doing this, you will get a lot of deck capacity. As you win, your level will go up by 2 or 3. By the time you get to 4500 capacity, your level will be 999 and you can put any card in your deck. It is recommended that you maximize your capacity to 9999 so that you can make any deck desired not worrying cards that you cannot put in your deck. You should put more effect monsters such as Mythical Beast Circuit, Revival Jam, Dark Necrofear, etc,. in your deck.
Go to the machine at the card shop and enter the code 99267150. Buy the Five God Dragon at the front counter. Also, enter the code 62873545 to buy Master of Dragon Soldier at the front counter. You will need to sacrifice three monsters.
When buying, make sure that you buy a very strong card, probably after getting locator cards from Roba, Bonz, and Rex. Also, make sure to buy level 4 monsters with 1400+ or more instead of just buying a card with an attack of 900; you will save more money. Also, buy some trap and magic cards such as Raigeki, Torriental Tribute, Sword of Revealing Light, Monster Reborn, and Change of Heart.