Magician mode
Successfully complete the game, then start a new game and enter "FIREBALL" as a name. If you entered the code correctly, the word "Magician" will appear on the option screen. All trading cards will be available under the DSS option.

Fighter mode
Successfully complete "Magician" mode, then start a new game and enter "GRADIUS" as a name. If you entered the code correctly, the word "Fighter" will appear on the option screen. Nathan will be stronger and able to sustain more damage. There are no trading cards in this mode.

Shooter mode
Successfully complete "Fighter" mode, then start a new game and enter "CROSSBOW" as a name. If you entered the code correctly, the word "Shooter" will appear on the option screen. Nathan will have a substantial number of hearts, extra sub-weapon damage, and can use the Homing Dagger sub-weapon in this mode.

Thief mode
Successfully complete "Shooter" mode, then start a new game and enter "DAGGER" as a name. If you entered the code correctly, the word "Thief" will appear on the option screen. Nathan stats will be reduced in both the value they start and increase with each level, except with LCK (Luck). Nathan will start with the value of 1600 LCK, and will gain an additional 160 LCK with each level (so at level 11 he will have 3200, and 4800 at 21, etc.).

Spinning attack
When using the whip, hold down Attack to make it spin around in a circle. It will act like a shield, so you cannot get hit by small enemies around you. Note: You cannot move while doing this attack.

Defeating Dragon Zombies (Twin Dragons)
To defeat the Dragon Zombies easily, whenever you get hurt, jump up to the platform by the door where you entered the room and activate the Jupiter + Mandragora DSS combo to heal yourself. A fireball may hit you every once in a while, but it is very rare.

Defeating Death
To defeat Death very easily, just activate the Jupiter + Manticore DSS combo. His sickles cannot hit you, and by this point in the game you will probably never run out of MP because this combo will use it slower than you restore it.

Use any DSS card combination
Note: You must have at least one action and attribute card. Equip an action and attribute card and press L (the DSS button). Immediately press Start, go into the DSS, and pick any card no matter if it is unknown or not. Note: This may require a few attempts. -From: ZCalic@ahaplanet.com

Use DSS in Battle Arena
In the Battle Arena, equip a good DSS Summon Combo (for example, Uranus + Cockatrice). Press Start, select "Items", then "Use", and use a "Mind High" (not a "Mind Restore" -- however they can work, but you will need to be extremely fast). Immediately after exiting the pause menu, press the DSS button. When your character is done casting, press Down, Forward, Up, Attack. If done fast enough, you should have pulled off a summon in the Battle Arena.

Enemies that drop DSS cards
The following is a list of enemies and locations that drop various DSS cards: