From purely an aesthetic perspective, the artistry and design on display in the Final Fantasy set are top quality, especially when looking at the Through The Ages reprints of classic Magic: The Gathering cards that feature art from longtime series mainstays like Yoshitaka Amano or Tetsuya Nomura
Koh, the Face Stealer Koh, the Face Stealer has to be one of the coolest spirit world creatures in the Avatar: the Last Airbender animated TV series
Land cards with basic land types have intrinsic activated mana abilities associated with those types
Use template numbers as a seatbelt, not a religion
Theres a funny card, Viashimo Heretic which basically deals damage equal to the total costing cast of an artifact which you can destroy too
For example, Brainstorm could be nerfed and brought back into Historic, but Brainstorm is such an iconic card that the developers wouldn't want to alter it