What's the rarest Magic card in existence?
Power Nine
The Power Nine are considered to be among the most powerful cards in the game. All nine cards are of the rarest level of rarity and were printed only in the Alpha, Beta, and Unlimited sets in late 1993 to early 1994.[3] Currently, all of the Power Nine cards are restricted in the Vintage tournament format[4] and banned in Legacy,[5] the only tournament formats where they would be legal otherwise, and all except for Timetwister are banned in the Commander format.[6]
Magic: The Gathering formats
While in Pauper only common cards are legal, in Peasant a deck may contain up to 5 uncommon cards and the rest must be common. Peasant Magic was created by Rob Baranowski who felt that players with limited access to cards should still have an opportunity for competitive play. Tournaments for this format have taken place at Gen Con since 2001. However, the original banned list is considered to be outdated and most tournaments are played by the rules of the largest active Peasant community.