Castlevania: Circle of the Moon/Secrets

Unlockables

 * For the different gameplay modes available after beating the game, see the Getting Started page.

Non-existent card combinations
It is possible to use DSS DSS Cards that you haven't found yet. Select a card combination that you actually have. When you activate the DSS, Nathan flashes from normal to black to glowing yellow. As soon as he goes to black, pause the game. In the DSS menu, select the combination that you want to use, and then unpause. You have now activated the combination that you just selected. This will last until you deactivate the DSS, at which point you will have to redo the glitch from the beginning.

Stat-boosting
Some card combinations boost stats like strength, intelligence, and defense considerably when activated, others have no effect or even reduce your stats. You can exploit a glitch to make attacks stronger by swapping cards in mid-use. This really only works with summoned creatures as they are on the screen long enough. To perform the trick, equip the combination to get the summon that you want to use, and then use it. While it is being summoned, equip a combination that boosts strength. The game will determine damage based on current strength, not your strength when you started the summon.

The other time when this is highly useful is when using the Item Crush ability (Pluto/Salamander combination). As soon as the Crush starts, switch to a strength-boosting combo to do additional damage.

Curing poison
When you activate the Jupiter/Black Dog card combination, it puts you in a poisoned state, and when you deactivate the combo, it gets removed. That is to say, the system sets your state to normal when the DSS is deactivated - not what it was before you activated the combo. That means you can cure status aliments like poison by activating and then quickly deactivating the combination. You can even use the combination even if you don't have the cards yet.

Magic in the Battle Arena
When you enter the Battle Arena, all of your MP is drained and if you restore your MP, it gets drained again. However, it takes a moment for all of your MP to disappear, so if you are fast enough you can get off a spell. Summons are the only spells that can do enough damage with a single casting, however it takes a moment to enter the button combo to use it, so you need to have far more MP than is required to actually cast the summon. Practice the combo before entering the Arena so you do slip up and waste an item.