I don't play Yu-Gi-Oh, but this card's presence invalidates this as an actual post since it has negates the mention of Magic as per the formula:
Iff (X+Xc)+(-1(Y+Yc)) ≤ 0, Post doesn't count
where X is equal to the number of times Magic is mentioned, Y is the number of times Yu-Gi-Oh is mentioned, Xc is equal to the number of Magic cards shown and Yc is the number of Yu-Gi-Oh cards shown.
See? It's science!