A card had to carry a spell model and be capable of activating that spell model as well, which was an extremely demanding task.
So 1-Ring Spirit Cards were common. Compressing a single spell model into a card was relatively easy.
Although 2-Ring Spirit Cards were rarer, they were not particularly uncommon. They merely required compressing two nested spell models even further.
But at the 3-Ring level, three spell models had to be nested within one another and compressed into a single Spirit Card, making the technical difficulty increase geometrically. To lower the difficulty, one had to expand the size of the Spirit Card itself.
That was why 1-Ring Spirit Cards and 2-Ring Spirit Cards could both be as thin as an ID card or bank card.
The 3rd Ring Spirit Storage Card in Duke's hand, however, was practically the size of a phone—extremely thick and extremely heavy.
"Ordinary Card Master techniques probably won't work on this Spirit Card. Of course, it isn't broken; it simply has no spirit energy left." The more Duke looked at it, the more he hated to let it go. As a highly skilled Card Master, he had a unique fondness for Spirit Cards.
The material of the 3rd Ring Spirit Storage Card was somewhat like crystal, but it was not as cold as crystal.
"Mm, it would be more accurate to say it resembles acrylic. It's slightly transparent, and you can vaguely see the structure of the card core inside."
The surface of the Spirit Card was covered in winding, jagged patterns. These patterns were a type of contact-based spirit-energy terminal.
The Spirit Storage Card supplied power to spirit artifacts or puppets through these terminals.
"It's truly beautiful!"
Duke slipped the 3rd Ring Spirit Storage Card into his pocket. Only then did his gaze