Elemental cards that were randomly distributed around the world, each granting the owner a unique ability for 24 hours, but there are only a couple of rules you need to know before using them: 1. You can only use it 3 times. 2. Once you use it for the third time, the card will disappear. 3. You can combine the cards the way you want And finally, the most important thing: When the card disappears, it will take all your memories with it, so you will forget abour the existence of the letter. You must use them wisely.