The very first spoiler from upcoming PvP set is a legendary troop.
Master Champion Mechanics
HEX development team were involved in development of World of Warcraft TCG. Although I had never had a chance to play the game, one of the game mechanics caught my interest was the concept of “master champion.” Basically, it’s a system where champion ascends to more powerful form. This is not new to HEX, but whenever they introduces one, I am thrilled and confirms the versatility of the core game design that HEX has, compared to more casual oriented dCG.
Master deck mechanics
This is a new game mechanics. Not only champion transforms, but this time the deck transforms. Now all we know are the new deck will have 3 cards, and not sure beyond that how the deck is modified i.e. whether the deck contains only 3 carders with more than 4 copies, or these special 3 cards are added to your original deck, or perhaps even allow player to build separate deck before hand. The latter is most unlikely scenario, but HEX now just have opened up a whole new possibility of game design space.