In other words, Spirit of the Dead is a LOT worse than people seem to realize, its lack of consistency is its downfall. Bwonsamdi, the Dead on the other hand, provides consistent value even when it isn't played alongside Spirit of the Dead. A 7 mana 7/7 that removes dead draws (pun intended) from your deck is actually pretty good, and I imagine he will be seeing play in a variety of Priest decks.
When it comes to Combo decks, Spirit of the Dead is hot mess. I feel like Priest is heading toward a mid-range/agro route this time around, using Spirit of the Dead andBwonsamdi, the Dead to bring back your fallen threats. Surrender Into Madness could be a thing. In other words, I agree with your assessment but there is no denying that Spirit of the Dead is a powerful card in concept.
I don't know man, a midrange Spirit of the Dead Priest with Bwonsamdi, the Dead as a finisher sounds good in theory but it wouldn't be able to keep up with aggro and I doubt it could go toe-to-toe with the heavier control decks. To be honest, it sounds like fun to play (and fun to play against) and I think it's about time for Priest to have an expansion that doesn't buff their control decks to the point of absurdity. If I manage to get myself a copy of Bwonsamdi, the Dead then I will definitely be playing this deck, I just don't think it's going to be the infinite value powerhouse that people are saying it'll be.
Spirit synergizes very well with cauldron, lyra, test subject, twilight's call, vivid nightmare, devilsaur egg, radiant elemental. You can combo vivid nightmare into radiant and whatever row first, then put this down and attack them into your deck.
I love the new direction priest is going, infinite value combos.
Mecha'thun decks are consistent because they don't need to interact with their opponent to activate their combo. Spirit of the Dead requires you to take the risk of playing a combo piece early in the hopes that your opponent doesn't shut you down by either killing the combo piece before Spirit of the Dead arrives on the board, or killing Spirit of the Dead with a board clear before it's effect can trigger. CallMeKelthuzad is right, this card is trash.
Dude - you don't even know what the "combo" is yet. No one does. We've seen like 15% of the set lol.
Further, my point wasn't about the viability of this card or Mecha'Thun, it was about the pace of the metagame. Two entirely different things.