Whispers of the Old Gods is the third major expansion for Hearthstone.

After all those additional cards, plus two smaller additions to the game in the form of solo adventures, it's easy to imagine the designers are running low on creativity.

The new "standard" format which limits players to basic and relatively recent cards could be seen as a desperate attempt to keep the game interesting as innovation runs dry.

You could be forgiven for thinking either or both of these things are true. I wondered about them myself when the expansion was first announced. The reality is quite different. The reality is a thrilling shot in the arm.

Mutating

There are 134 cards in this expansion, but it feels like a lot more. Like the other major expansions before it, Whispers is built around a new deck archetype and a novel supporting mechanic.

In this case it's C'Thun, a powerful new minion that everyone gets for free. Many of the new cards interact with C'Thun, whether it's in your deck, your hand, or on the board, buffing its stats or feeding off them to boost other cards.

Each time you do, C'Thun flashes up in the corner of the screen, showcasing his new numbers. If he hits the board, he unleashes his attack as random damage, as well as being a massive presence in his own right.

Watching him build and build, wondering when he might appear in a hand or in play, is like watching the timer on a bomb. The tension ramps up and up until - boom! The game is changed forever, and often won by the summoning player.

Obviously this works best with defensive classes who can stay in the game long enough to build C'Thun's stats and the ten mana he costs to summon.

Yet all the classes have gotten some fantastic new toys to play with in Whispers, whether they want to run C'Thun decks or not. It really is a marvel of design to have shovelled so much creativity into one card set.

Expanding

Paladins, for instance, get two new viable deck styles. Divine Shield has always been a popular class effect, but with Steward of Darkshire and Rallying Blade you can now build a whole deck around it.

Hearthstone has also been pushing Murloc-themed Paladin decks for a while, but none of the previous cards really made it take off. Now, with the aforementioned Steward and the Vilefin Inquisitor, it's finally dragging itself out of the swamps and onto the board.

Almost every class has one or two new powerful archetypes to mess around with.

Shamans, the weakest class in the current meta, have a new Evolve keyword that can instantly upgrade cards already in play to a costlier random alternative.

But the designers haven't forgotten the class needs a boost to stay competitive. Flamewreathed Faceless and Thing From Below bolster existing face Shaman and totem Shaman archetypes magnificently.

Transforming

Playing right now, Hearthstone feels as fresh and exciting as it's ever been. You can't be sure of what you'll meet in the meta, and you're often still guessing two or three turns in as you watch your opponent's play for hints of what they're building toward.

Keeping a game with such a bewildering array of effects in balance is an impossible order. Some cards and some deck types have always been much better than others.

And there lies the only downside to this influx of fresh blood. Although there's now a wide range of decks in circulation, they're falling into two predictable categories, trading off against each other.

Everyone with the right supporting cards wants to run C'Thun for both the novelty value and the power. Everyone else is running highly aggressive decks hell bent on killing C'Thun decks before they can buff and summon that unstoppable monstrosity.

Mid-range builds have gone out of the window. If you have a particular aversion to fast damage aggro decks, the current meta isn't going to be to your liking.

Zoolock, in particular, has made a big comeback with Possessed Villager and Forbidden Ritual able to flood the board with mini minions.

Things will calm down soon enough. They always do. The dust will settle and the glut of experimentation will solidify into a a few favourite archetypes for each class.

Yet when it does, it feels like there will still be a whole lot more possibility in Hearthstone than there was before the Old Gods came to visit.

They've transformed Azeroth, but instead of laying it to waste, they've managed to make it lots more fun.