Hearthpwn

1. Completely shits on druid. They ramp with wild growth and nourish and on turn 6, BAM. Both players are reset to 5 mana crystals and druid have to wait 4 more turns to UI (HUGE fning deal). Also, strong wincondition against hadronox/malygos combos, both of which can now be pushed away a couple of turns, long enough to put his health to 0.  

2. Rip Mecha'thun decks and any variations of it. Even if only 3% of the meta was mechathun decks (Druid, Priest, Warlock), simply having this card in your deck gives you 100% winrate (unless you make a mistake and play it early of course). 

3. Shudderwock and any other late-game win-conditions like Jaina? Can be played around much better. Doesnt mean youll necessarily win the game, but preventing the Jaina from coming down on turn 9 is HUGE. 

4. Any potential future OTK combos? Well, what most OTK combos need is Mana. Usually, these decks are designed to cycle into their combo, which takes up multiple cards in their hand and 9-10 mana. Well, that can ALSO be played around now, and those otk decks have a very hard time with survival when they cant play their combo to win. 

Conclusion: Only shitty matchup this card has is aggro, where its practically useless. But every single non-odd control deck out there will play this card, as it gives you significantly better winrates against many different decks and flat-out wins games against certain archetypes. This card is meta-defining!

For Rogue: Recommend crafting Odd rogue, as it is quite cheap (you'll have to craft baku the mooneater, but baku is useful in a ton of other decks that you might want to play down the line) and one of the most powerful decks at the moment. Also, if you have leeroy and van cleef, you could build a miracle/tempo style deck (you'll have to craft 2 versions of Faldorei Stridor (epic))

For Warlock: Zoo Warlock is always a useful and cheap deck. In order to have an optimal winrate, you might want to consider crafting the Soularium, but the deck is playable without it as well. Control/Cube Warlocks play a lot of new legendaries and might be a little too expensive. 

For Priest, you might find it a little harder to build a cheap deck, but you can try building a control priest if you already have alexstraza. You'll have to craft shadowreaper anduin and a few epics, but its a pretty fun deck imo. You could also try going down a mecha'thun path (?) as mechathun also works in druid and warlock, but that might be quite exensive. 

All of the decklists can be found on hsreplays.com, and you can compare different classes, different versions of the deck and even the winrate. Highly recommend you use it at the start to help you figuer out the core cards for whatever deck you'd like to make. Have fun! 

All fantastic changes.