Magic Origins also returned with double-faced cards, but this time the backsides were all planeswalker cards
Having jump-start on this card makes it especially powerful as you can essentially do a one-two punch with your strongest creature, which could potentially close out a game
If that's another creature, it gains the following abilities until end of turn
Mirror Box doesn't stop you from sacrificing or exiling your tokens, but it does turn off the "legend rule", and it pumps the original creature based on how many copies you have in play with the same name
Speaking of a horde of token creatures, thats a perfect use for transforming Westvale Abbey into Ormendahl, Profane Princewho just so happens to be another Demon
Canyon Slough and Dragonskull Summit are your best for black-red, while Fetid Pools and Drowned Catacomb are the clear winners in blue-black