I believe that is from yu-gi-oh an old show. It could also mean that that magician had the sigil of certain spirits on a card and used it that way to summon. Could actually be a way to keep all your sigils neat and hidden.
Re: Card Magic
By: WhiteRav3n / Knowledgeable Jan 09, 2012
Post # 8
The tarot has both negative and positive cards, so of course it can be used for any purpose. I actually found an italian 10 of coins by my house. I know a neighbor of mine practices, but I don't know which one. Obviously they're in some financial trouble and were attempting to draw the meaning of the card into their life.
ooooh also i am interested in stellar mages ppl i love anime it's japanese cartoon and one of them is about magic guilds and magicians in this anime my fav character is lucy she summons zodiac spirits she has keys and she shoves key into the water and she says "Open Gate Of The Water Bearer-Aquarius and mermaid with vasse comes from the water and she can use full power of ocean and seas.have you ever heared magic like this? maybe it's fail for someone but who knows anime he/she understand that i would like to be boy who summons zodiac spirits with keys i like it