The most obvious way to play this card is in Druid, that class already has a “draw your deck to win” archetype. The issue is that deck so consistently draws itself and survives to do it is due in large part to Ultimate Infestation, which would work for Mecha’thun for the most part if you draw Ultimate Infestation early. Mecha’thun requires you to play out all the cards in your hand with an empty deck, and Ultimate Infestation can be hard to survive playing if it’s the last card you draw (or even just close to the last). Some lists are floating around that use Gadgetzan Auctioneer to draw your deck instead, but you also have to be concerned with Skulking Geist. Mecha’thun > Innervate > Naturalize is the most consistent way to trigger the deathrattle once the conditions are met, and Geist puts a significant wrench in that plan. There is however another class that can reliably meet Mecha’thun’s conditions without having to deal with Skulking Geist, Warlock, and it comes with a handy tool to skip the end-game struggle to empty your hand.
Warlock takes care of the empty deck requirement with its hero power, but how do you destroy Mecha’thun the turn you play it? Enter the underutilized Warlock spell Cataclysm. Not only will Cataclysm destroy Mecha’thun along with any other straggling friendly minions, but it simultaneously takes care of the empty hand requirement by discarding it all. Yes, that is fourteen mana, but there’s more. Also coming with “The Boomsday Project” is Galvanizer, a 2-mana minion that reduces the cost of Mech minions in your hand by one and Mecha’thun is, as the name implies, a Mech. If you play two Galvanizers with Mecha’thun in hand its cost is reduced to eight, leaving two mana left over if Mecha’thun is played at ten crystals. Still not enough to play Cataclysm, but it is enough to play another underutilized spell: Bloodbloom. Bloodbloom changes the mana cost of your next spell to cost health instead, so as long as you have at least five health left you can play all these together to destroy Mecha’thun and watch him take your opponent down with him.
What does the rest of the deck look like? The essential combo pieces are Mecha’thun, two Galvanizer, Bloodbloom and Cataclysm. These are all even-costing cards, which means it can be played with Genn Greymane. One-mana Life Tap is a lot easier to work into the curve than the normal two-mana version (considering how many times you need to press the button this is a deck where the odd hero power might actually be worthwhile, but alas it doesn’t fit), and those decks tend to have a lot of healing potential to counteract all the tapping the deck requires.
Mecha’thun Even Warlock Card Choices
- Acidic Swamp Ooze – Malygos Druid is going to be big at the launch of The Boomsday Project, and while the deck will lean less heavily on Twig of the World Tree, you still can’t afford to let them have a 20-mana turn.
- Spirit Bomb – This card is likely to be really helpful against decks like Odd Rogue. Even Warlock struggles to remove cards like Hench-Clan Thug when they’re played on curve, and this gives it a way to do it. The cost of four health might be too high for a deck that’s constantly sacrificing it’s life, but we’ll have to find out.
- Skulking Geist – Naturalize gets played in many Druid decks anyway, but it’s an essential component of the Druid version of this deck as well. Geist gives this deck a significant edge in the race to Mecha’thun, and regardless of whether or not these decks are viable you’re bound to run into the Druid version a lot in the first few days of the expansion.
- Genn Greymane – This deck needs to Life Tap a lot, and at one mana it’s much easier to fit into the curve.
- Mountain Giant – Although this is a combo deck it’s hard to pass up a turn three 8/8, and the pressure this puts on control decks will have them worried about surviving more than racing to their game-ending combo.
- Bloodreaver Gul'dan – The whole reason to play this combo in Evenlock is for the one mana Life Tap, but Gul’dan is still useful. You might not Life Tap at all in the latest stages of the game as your health is likely to be pretty low by that point. Gul’dan will help keep you in the game and buffer your health to allow the use of Bloodbloom for the combo. Also, playing this card often means a win right there against aggro decks.
Mecha’thun Even Warlock Mulligan Strategy & Guide
Against aggro you want to live and against control you want to race to your combo as fast as possible.
VS Fast Decks
Higher Priority (Keep every time)
- Defile – Clears even the stickiest boards, slowing down aggressive strategies.
- Doomsayer – Played on curve Doomsayer can often cause aggro decks to essentially skip a turn.
- Vulgar Homunculus – Efficient Taunt minion for the cost, and helps activate your spellstone.
- Hellfire – Played on curve Hellfire clears most boards and upgrades your spellstone.
Lower Priority (Keep only if certain conditions are met)
- Spirit Bomb – Throw this back against Odd Paladin but keep it against Odd Rogue. This is in here to answer Vicious Fledgling and Hench-Clan Thug.
- Lesser Amethyst Spellstone – Keep if you have a way or two to upgrade it, but toss it back if not.
VS Slow Decks
Higher Priority (Keep every time)
- Galvanizer and Mecha'thun – These are the worst cards to have as the last card in your deck because you need to play both Galvanizers with Mecha’thun in hand before your combo turn. Don’t bother keeping Bloodbloom and Cataclysm because you will draw them by the turn you need to use them 100% of the time (your deck will be empty the turn you use them).
- Mountain Giant – Turn three Mountain Giant can cheese some wins against control and will at least slow them down to some degree.
Lower Priority (Keep only if certain conditions are met)
- Acidic Swamp Ooze – Keep against Druid if you’ve been seeing a lot of decks with Twig of the World Tree. If you aren’t running into them a lot you could even consider taking the card out.
- Skulking Geist – Keep against Druid to remove Naturalize and maybe against Priest to remove Inner Fire and Power Word: Shield. Inner Fire is less important to that deck than ever thanks to Topsy Turvy but they still might run some and they will at least be playing Power Word: Shield.
Mecha’thun Even Warlock Play Strategy
VS Aggro Decks
You might not combo out against aggro very often. Your main win condition against these decks is likely to be Bloodreaver Gul'dan. Try to keep your health high and clear the board as much as possible. If you can safely play Gul’dan it will be hard for most aggro opponents to stick minions and pressure your life after.
Against most decks it is probably ok to waste Bloodbloom on something if need be, but Rogue decks take special consideration if Baku the Mooneater doesn’t show up at the beginning of the game. These decks might play Myra's Unstable Element and then Lab Recruiter a bunch of Fal'dorei Striders into their deck. The viability of this remains to be seen but endless 4-health minions means these Rogue decks won’t run out of threats as fast as other aggro decks would, and the Mecha’thun combo might be your only hope.
Apart from clunky Mech decks, you can expect not to run into as much aggro as usual for the first few days of the expansion as players will be eager to try out slower combo decks like this one. If the meta ends up being aggressive consider removing some of the anti-control cards like Mountain Giant in favor of more survival tools.
VS Control Decks
Plan A is to win with the Mecha’thun combo but depending on your opponents hand you might be able to pressure a win with Mountain Giants.
Once you’ve drawn all your combo pieces don’t be afraid to Life Tap when it would cause you to overdraw. Most of those cards won’t end up mattering and it’s more important to empty your deck than make use of them. Keep track of your life total, especially against Malygos Druid. They can play Malygos and double moonfire for 12 at any point after they reach nine mana, so stay above that against them. Also, you can’t Mecha’thun combo if you are below five health. Bloodreaver Gul'dan can be helpful as you approach the last few turns of the game to buff up your life enough to play your combo.
Mecha’thun Even Warlock Card Substitutions
The Mecha’thun combo doesn’t require Genn Greymane, but given how much easier it is to Life Tap with one mana than it is with two I think it’s better that way. You could try a control Warlock shell with Voidlords and odd-cost removal, but that’s probably slower than opposing combo decks and you miss out on a lot of the early pressure that way. Also, if you have a Voidlord out on the Cataclysm turn it will leave Voidwalkers behind to disrupt the combo. This interaction is unlikely to be relevant very often but it’s something to consider.
Sticking with the even strategy, the list has some options. The list above is somewhat light on removal and doesn’t abandon the big minion pressure plan. The list could be adjusted to include Siphon Soul and Twisting Nether. Siphon Soul in particular might end up in the refined version of this deck just because all the Life Tapping demands just about as much healing as you could fit in. With that in mind Drain Soul could be a consideration, especially if you add Bloodmage Thalnos to the list. Thalnos has synergy with both Drain Soul and Defile, drawing a card on top of that which equates to healing for two in many cases as that’s one less time you have to Life Tap. Lifedrinker can also be considered if the deck just needs every healing card it can use.
A second copy of Cataclysm is unlikely to be worth it considering you have to discard your hand to use it, but a second copy of Bloodbloom could be useful in case you’re presented with the need to use one early on. I probably wouldn’t, there is already a back-up strategy with the normal Evenlock gameplan.
If you wanted to lean more heavily on the combo, Hemet, Jungle Hunter is something to consider. Hemet reduces your deck size without you having to damage yourself. For this you would remove most of the higher-cost minions and add in Bloodmage Thalnos and Loot Hoarders. You would also need the second Bloodbloom because you have to draw one of them before you play Hemet, along with both of your Galvanizers. You could add Witchwood Piper to help grab the Galvanizers (which may be worth it anyway, you don’t want Galvanizers to be the last card in your deck), but remember it won’t always hit them, especially with all the extra 2-drops. If this is the best way to play the deck, that means it might be better outside of the Evenlock shell, as you could destroy a lot more cards with Hemet if you include one and three mana cards.
With the new Magnetic mechanic, Mech decks will be popular for at least a little while after the expansion launches. Spellbreaker will be worth including to remove Magnetic buffs if you run into these decks a lot.