Is the staple Warlock spell useful in the current Hearthstone meta?

Over the years, there have been many variants of Control Warlock. From the early, threat-heavy Handlock days to full anti-aggro lists focused on removing anything and everything that even thinks about entering the battlefield.

Throughout all this time, one card from the Basic set has been an automatic inclusion in every single list. It's not big. It's not flashy. But it gets the job done. That card is Mortal Coil.

However, with the new cards from Knights of the Frozen Throne, it might finally be the time to ask whether Mortal Coil deserves a spot in the deck anymore. I think it’s time for Mortal Coil to finally give up its status as a Control Warlock staple, and I’ll explain why.

Back to TopWhat makes Mortal Coil so good?

One mana spell. Deal one damage to a minion. If that kills it, draw a card.

That does not sound particularly impressive. Only one damage, only to a minion, and it cannot even go face! Way worse than Moonfire! The real beauty of Mortal Coil does not lie in its ability to deal one damage, but in its ability to draw a card. In card games, cards that have an effect and additionally draw another card to replace themselves are called cantrips.

Cantrips can be useful in multiple ways. The main way they are useful is that they allow you to thin your deck, and thinning your deck is always good. You want to have as few cards in your deck as possible so that you can find the important cards whenever you need them. Adding two copies of Mortal Coil to a Warlock deck effectively allows you to build a 28-card deck and have just a little bit of an edge in finding the right answers.

Cantrips can also be useful if the number of cards you play in a turn matters. Warlock does not currently have cards where this would make a difference, but there are a couple of such cards in Hearthstone: Sherazin, Corpse Flower in Rogue, for example, and the upcoming Priest legendary weapon from Kobolds and Catacombs, Dragon Soul. Of Hearthstone’s neutral cards, Gadgetzan Auctioneer benefits the most from cantrips, but it’s not like Warlock has any issues with card draw anyway.

Therefore, the main reason to play Mortal Coil in Control Warlock has been to thin the deck. Sure, it is sometimes a nice bonus to hit that one extra damage after a Hellfire to kill a four-health minion, but by far the main use of Mortal Coil has been to kill one-health minions and draw a new card.

Mortal Coil’s effectiveness figures tell the same story: the card is most effective against Hunter, Paladin, and Shaman, the main classes to consistently pump out one-health minions. In those matchups, the card continues to be good throughout, whereas in other matchups its value is either not that high to begin with or rapidly shrinks over time, representing the difficulty to activate its draw effect later in the game.

Mortal Coil is a conditional cantrip unlike Hammer of Wrath in Paladin that always draws a card in addition to its effect. However, as an upside, Mortal Coil is very cheap at one mana, even undercosted for a card draw effect, for which Hammer of Wrath pays a hefty premium. Overall, it seems like a good deal, and it is. But is it good enough in this meta, with this card pool?

Back to TopKnights of the Frozen Throne changed the environment

Every expansion always changes the meta, but there are three specific cards from Knights of the Frozen Throne I have in mind when it relates to how good Mortal Coil is right now. No other expansion has changed the environment for Mortal Coil in particular: there will always be minions, and there are always early minions with low health, even if Fire Fly from Journey to Un’Goro partially heralded a new age of one-drops with a 1/2 statline that cannot be killed by Mortal Coil alone.

Knights of the Frozen Throne changed something else. It changed how Warlock’s own early game functions. There are three key cards in this: Defile, Tainted Zealot, and Drain Soul.

Defile has come to define how Warlock deals with early board states. It deals one damage to all minions and casts itself again if any minions die. Warlock removal has become a game of setting up that perfect 1-2-3-4-5-6 curve to be cleared out with Defile.

Sometimes, the curve can be a little different. Tainted Zealot, in particular, affects things. With that +1 spell damage and Divine Shield, Defile turns into a 2-4-5-6 curve with the Tainted Zealot itself filling the four damage slot. The real killer combo right now is Tainted Zealot and Defile together with a Mistress of Mixtures, which fills out that two damage slot and ensures at least five damage to every minion on the board for five mana alongside four healing to both players.

With such a powerful tool available to Warlock, responding to early one-health minions with Mortal Coil can even be detrimental – you may want to have a low-health minion on the board to activate Defile. Furthermore, what I’ve found myself using Mortal Coil for more and more often is setting up that Defile play and smoothing the curve to get everything killed with a single Defile. Now, when Mortal Coil is used in this way, it is a worse Moonfire. It does not draw you a card. It is no longer a cantrip.

Sometimes, you can set up the Defile play with a gap between the last two minions, get that biggest minion down to one health, and finish it off with Mortal Coil. A gap anywhere else does not give you a board clear, there you need to smoothen the curve before Defile.

Furthermore, should you have some need for early damage, Knights of the Frozen Throne provided an alternative for that too: Drain Soul. For just one more mana, you can deal two damage to a minion and heal yourself while doing it. Drain Soul can happily be used to smooth those health curves for Defile regardless of whether you can set it up so that Mortal Coil could draw a card or not, and Warlock is in desperate need of early healing, so it fits the class like a charm.

There are two other Knights of the Frozen Throne cards that affect Mortal Coil in particular: Prince Keleseth and Skulking Geist.

Prince Keleseth further lowers the value of Mortal Coil later in the game, as there will simply be no one-health minions around after the Prince buffs them all by +1/+1.

Skulking Geist, on the other hand, comes into play in matchups that go the full distance and end in fatigue: Mortal Coil becomes yet another innocent victim of the Jade hate card as Skulking Geist ruthlessly eats all copies of Mortal Coil from your hand and deck. In fatigue matchups, it’s the copies left in the deck that matter, taking you a step closer to fatigue. As Control Warlock decks themselves make liberal use of Skulking Geist right now, having Mortal Coils in the deck also limits your ability to play your own Skulking Geist in some matchups.

Never before has Mortal Coil taken such a hit from multiple new cards from a single expansion!

There are also overall meta considerations. With Mortal Coil being at its best against Hunter, Paladin, and Shaman, and none of those classes being at the top of the pack right now, the relative value of Mortal Coil is down. This can of course change with the meta, and is likely to change again with the release of Kobolds and Catacombs.

Back to TopWhy is Mortal Coil still used in almost every Control Warlock deck?

None of the above considerations make Mortal Coil strictly bad in the current meta. You can still use it to kill one-health minions and draw a card. You can setup Defile clears that leave one minion alive at one health and Mortal Coil that down. But the number of good targets is in decline and Mortal Coils are spent more than ever for uses that do not draw a card, which is wasteful.

Mortal Coil is also a card that has been used in all Control Warlock decks forever, so some of it may come down to the power of habit. It just feels like it belongs there, even when the overall card pool has created an environment where it is less good than before.

It is quite late in Knights of the Frozen Throne, and I have to admit that I only cut Mortal Coils from my decks in the past few days after reviewing my personal statistics and noticing that my use trend for the card had changed for the worse. Others have drawn different conclusions, and provide more support for Mortal Coil instead of cutting it. There is room for many approaches in Hearthstone – I can merely offer you a viewpoint to consider your deeply-held beliefs.

Back to TopControl Warlock in late Knights of the Frozen Throne meta

So, what does an effective late Knights of the Frozen Throne Control Warlock deck look like? Here are two decks that share the same theme, one with Mortal Coils, and one without.

StanCifka’s Control Warlock (November 2017)

StanCifka played this Control Warlock deck to Legend in November. It is a heavy removal build, running two copies of Twisting Nether and capable of running most decks out of threats.

Notice how StanCifka has chosen to include Mortal Coils and provide additional support for them: there is a Bloodmage Thalnos in the deck in addition to the usual two copies of Tainted Zealot. With three such activators, StanCifka’s build has a good chance to cast some empowered Mortal Coils, Drain Souls, and Defiles – and he can easily afford to spend one of the spell damage minions on something else than Defile, such as Mortal Coil dealing two damage to get that valuable card draw.

Back to TopOld Guardian’s Control Warlock (November 2017)

I cannot boast the same level of performance as StanCifka, having only piloted my build to rank 5 in the early days of the November season whereas StanCifka already hit Legend on November 5th. Maybe you can take this to mean that Mortal Coil is still the better card choice, or maybe StanCifka is merely the more accomplished pilot – and I would venture to guess that the latter is true at the very least.

Be that as it may, cutting Mortal Coils open up some tech slots for the deck. This build is also of the heavy removal variety. You know the drill: if it lives, siphon its soul or cast it out into the nether. All that removal takes up a lot of space, and it is usually difficult to find room for threats or tech cards.

There is no Bloodmage Thalnos here, as there are fewer spells that need additional spell damage support, but there is room for Spellbreaker, Abyssal Enforcer, and The Lich King for that precious silence effect as well as some more threats for those matchups where you want to be more proactive. You can also use other tech cards as needed in those vacant slots, whereas usually there is hardly any room for techs when Mortal Coil is included.

Back to TopWhat is the future of Mortal Coil?

When building a deck, you should always be ready to question the role of each and every card in it. For example, many Control Mage and Control Warlock decks have cut Doomsayers over the course of Knights of the Frozen Throne, something that seemed unimaginable just a little while ago.

It’s the same with Mortal Coil: it should not be included in decks blindly, but with proper support and facing the right meta, it can be a valuable addition. That said, I’ve been playing Control Warlock without Mortal Coil lately, and it has performed better than I would have expected until I reviewed how my cards are actually performing for me.

What about you, will you give Control Warlock without Mortal Coil a try?

"Ville "Old Guardian" Kilkku is an analytical Hearthstone content creator and a regular legend player on the EU server. In addition to his articles, you can find his Hearthstone videos on Youtube and stream on Twitch. If you have any questions or comments, you can connect with him on Twitter.