Emet-Selch, Ascian K'rrik, Son of Yawgmoth requires a ton of black cards to do much, and its a card thats much more aimed at something like Commander than Limited
Heartfire Hero Unlike Cacophony Scamp or Fireblade Charger, Heartfire Hero hits each opponent, which feels like a must-include in the crowded Boros equipment EDH space
It can die quite easily to very cheap removal in the format, and it doesn't give you any sort of value up front
On information and belief, Miller maintained access to these things even after terminating his relationship with Upper Deck and used, referenced, and/or otherwise relied on them to create Lorcana for Ravensburger." Along with damages, Upper Decks is seeking "injunctive relief enjoining Ravensburger from publicly releasing Lorcana." This means the card game would be prohibited from launching (and clearly hasn't worked, considering the fact that it's now on shelves)