mtg cards info 7 Points Singleton 93/94 Old School Cartouche of Knowledge - Foil

There are lots of great examples, but one that particularly stuck with me was Academy Ruins by Zoltan Boros and Gabor Szikszai

The odds are extremely low so these cards are bound to be some of the most expensive non-chase cards in the game

Its main weakness is the time it takes to bring Atraxa, Grand Unifier into play, but once she is in, you will be golden

Similar to the Partner rule, instead of requiring Partner on both cards for two Commanders, you need a Doctor and Companion

There are also some nice cards that take advantage of the multiplayer format, but not loaded up in a way that makes everything seem overpowered