Were already seeing Zendikar Rising experiment with using different card types as the front side of these, which will affect deck-building and combo options across various formats (the front side determines how you can search for or target these cards when they arent in play)
How well designed were the decks
Ulalek also has a ridiculous ability in terms of complexity and power level
Necrosynthesis Enchantment Aura Enchant creature Enchanted creature has "Whenever another creature dies, put a +1/+1 counter on this creature." When enchanted creature dies, look at the top X cards of your library, where X is its power
Gengar H9 has a powerful attack that either burns or confuses the enemy Pokmon depending on the coin toss, but more importantly, it has the Pok-Power: Manipulate, which allows the player to place a basic Pokmon from the discard pile onto their bench and flip three coins to determine the amount of energy cards the player can attach to said Pokmon from the discard pile
Rule #6: The Sideboard still exists The unsung hero of many of my BO1 control builds is Fae of Wishes