And there will be four new heroes to lead the fight, each with their own hero power and "cards that create completely new playstyles and strategies".
(6) Genn Greymane (6/5): Start of Game: If your deck has only even-Cost cards, your starting Hero Power costs (1).
The expansion will also add a new Monster Hunt mode to the action, similar to Kobolds & Catacombs' Dungeon Run, that challenges players with a series of eight increasingly hard encounters leading into a big boss fight.
(3) Phantom Militia (2/4): Echo. They're back! In card form!
Pumpkin Peasant provides Life Steal. Worgen cards swap attack and health each turn they're in your hand, so you can hold onto them at different times for different results. Battlecry: Gain +3 Attack this turn. "Start of Game" means that including that minion in your deck and meeting its conditions will grant its effect at the very start of the game, much like Prince Malchezaar.
"Echo cards can be played multiple times on the turn you play them".
Rush is an alternate version of Charge, meaning the minion can attack the moment it is played, but only if it's target is a minion. Look for more of those keywords to pop up throughout the expansion.
The Witchwood card reveal livestream will begin at 11:00 am PDT on March 26 on the official Hearthstone Twitch.tv channel.
Ben Brode revealed another card at the end of his adventure, Hagatha The Witch, but all we can see is that she's a Shaman Legendary that costs 8 mana.
On top of all of that, there's a new single-player mode called Monster Hunt. The implication is that there will be more than one Worgen card in this expansion.