New universe's beyond idea
I believe the Supernatural TV series would make an excellent new universe beyond and bring in a lot of new people to MTG, the different decks would consist of; Angels, Demons, Humans, Monsters. An easy split to then make individual command decks for and have Possessed or Bitten commanders to help bridge over the colour schemes of you wished. The four horseman all the demi gods mentioned and so much else that the series offer could make for fantastic new cards and combinations.