Yo, I'm known as Kit Kastle to many and if you want my real name, I'll give you a letter every time you give me 20 bucks.

Artifact: Spirit Cards: The Spirit Cards are mystical cards that allow the user to use the abilities of the spirit inside the cards. As suggested, most Spirit Cards have a soul sealed inside of them and the user of the cards is able to interact with the souls in their cards in their mindscape. Also, the wielder, after training with the Spirit Cards for an extensive amount of time, may be able to physically manifest a body for a soul, but the process requires a large amount of energy to complete. They are usable by scanning them through the S-Driver (which is similar to a midnight blue version of the Dino Bracer from Dinosaur King). The user is then transformed into the clothes of the soul (which are shaped to match the user's gender) and gains that soul's abilities. Unfortunately, only those chosen to use a S-Driver as a Spirit Wielder can safely use the cards. Anyone else that attempts to access the card's power will become a Seiyokai, a darkness-oriented monster based on desire and destruction. Defeating a Seiyokai will return the possessed to normal, if the body wasn't completely destroyed, and the card that transformed them is absorbed into the S-Driver. Also, the S-Driver can track nearby Spirit Cards that have not been contracted to another S-Driver.

Story profiles I just come up with when I'm bored (If you want, go ahead and try to make the story yourself, with changes to fit your take on it. It's a OC challenge and a random idea I have)