or maybe a friendly prism that turns a boost school to a resist school example:use it on a myth wizard and it will turn a storm school spell into another school what do you think? reply please
I think that is too complicate for one card, because remember they have to draw the card and label it. So, it would be better to make multiple cards, instead of just one. Plus, people could cheat useing one card. They may already have the card you want, since those to are opposite. I was think of something indirect opposites, like life to ice.