A deck of 78 blank faced tarot cards is bound to your very soul.
These cards have the magical ability to seal and unseal anything into themselves, though this is not the true power of the cards. No, their true power lies in the ability to combine the things you've sealed in them. For example, if you take a "Gun" card and combine it with a "Lighter" card, you create a gun that shoots fireballs instead of bullets.
The cards also give you the ability of a professional magician: acrobatics, sleight of hand, mentalism skills and so on. There are some unfortunate side effects though. You get urges of kleptomania and theatrics.