Hearthstone's latest one-turn-kill combo is so absurdly complicated that streamers keep messing it up

There are few things the Hearthstone faithful love more than busting open a new expansion and rushing to find the most esoteric combo. Last time around, it was Shudderwock’s infinite loop of life-sucking damage (both in-game, and to your mental health), which was discovered on the first day of The Witchwood expansion. But honestly, I don't think I've ever seen anything quite as degenerate as the new Test Subject one-turn-kill combo which was unleashed yesterday in the first hours after The Boomsday Project launched.

I'm almost afraid to describe this combo because it's borderline impossible to parse what’s happening, as you can see from the clip above. But basically, it's a Priest deck that uses the new 1-Mana 0/2 minion Test Subject, and the new 0-Mana spell Topsy Turvy. Here’s a handy picture, created by reddit user u/PrepCoinConcede, showing what needs to happen in one turn to successfully complete the OTK combo.

Test Subject has a Deathrattle effect that returns any spells that have been cast on in to your hand, exactly like Primalfin Champion, an entirely forgettable Un'goro Paladin minion. Topsy Turvy is a spell that swaps a minion's attack and health, so your goal here is to cast a perfect cocktail of spells on Test Subject, and then kill it with Topsy Turvy to add those spells back to your hand. More specifically, you also need two Radiant Elementals, (which discount the cost of your spells by one Mana,) one Vivid Nightmare, (which summons a copy of a friendly minion with one health), and a Divine Spirit, (which doubles a minion's health). Lastly, you're going to want a Stonetusk Boar, which is where the real sickness begins.

If you're a genius, you might already be able to see where we’re going with this. But basically, you'll play Vivid Nightmare, Divine Spirit, and Topsy Turvy on your Test Subject. This will kill the Test Subject, returning you the spells, and leaving a 0/1 Test Subject from Vivid Nightmare on the board with a Divine Spirit effect. You will then cast the same spells on that Test Subject, cloning it again with Vivid Nightmare, and killing it again with Topsy Turvy, which will add double the amount of those same spells to your hand. APM permitting, you can keep doing this forever, providing a never-ending supply of Divine Spirits and Topsy Turvys. 

Then comes the charging pig. Sure, it might start out as a 1/1, but with a couple of those Divine Spirits, it won't be long until it's a 1/32. Throw on a Topsy Turvy, and now it's a 32/1. Taunt minion in your way? Don't worry, just play Vivid Nightmare to get more charging 32/1s to clear the way.

Pulling it off is about as ornery and finicky as it sounds. Yes the combo is deadly, but pulling it off without messing up has proven to be borderline impossible for many players. You can easily lose track of what spells are on what Test Subjects, and your hand size bloats so quickly when one of them dies that you can burn a crucial piece of the combo with one miscalculation. It's also a more time-intensive turn than any deck in the game's history. You have to buff and re-buff so many minions while also making sure you're not about to commit some fatal math error that roping out becomes a legitimate concern. 

On the bright side, this has lead to some truly amazing Twitch highlights. I spent much of yesterday watching Jeffrey "Trump" Shih mess around with the combo after raving about it in his pre-release theorycrafting. By my count he threw a half-dozen winnable games by botching the execution. Ever the sport, he posted some of the lowlights on his YouTube channel, which are embedded at the top of the page. It's a lot of fun to watch him fail, and it also makes me never want to try the deck myself.

Other pros have had better success. David “Dog” Caero piloted the deck throughout much of day one–he’s the guy in the clip above–and finished around a 50 percent win rate. However, a look at stat-tracking site HSReplay.net seems to confirm this is not a deck for us rank 15 chancers. According to its data, Test Subject Combo decks are winning less than 30% of their games on ladder. Oof indeed.

Nonetheless, the fundamental idea of the combo is solid, and I have to imagine that as the decklist gets more refined, and players get better at keeping track of their hand and the turn timer, there's a chance this abomination could morph into a new Shudderwock (which was also written off as a meme initially). Any chance to put an infinite damage combo on the board requires some serious consideration.

Speaking of memes, perhaps we’re overlooking the real combo menace: Mecha’thun. This one-card win condition, which initially looked like a joke for streamers to try to pull off, has already proven surprisingly viable in Druid and Warlock decks, both of which are good at drawing lots of cards and killing their own stuff. 

What's less fun and interactive: an infinite supply of buff  spells being pumped out by dying gnomes, or that bastard Malfurion cycling through his entire deck with Gadgetzan Auctioneer and auto-assassinating you with Mecha’thun-Innervate- Naturalize? Truly, this is the Sophie's Choice of Hearthstone. Stay safe and sane, people. It’s getting weird out there.