With the start of the Year of the Phoenix, Mecha'thun and all key cards of the deck in The Boomsday Project rotated to wild, making Mecha'thun Warlock a wild-exclusive archetype. For more information, see Game format.
Mecha'thun Warlock is a combo deck with Mecha'thun as its win condition.
Mecha'thun Warlock can be built in a variety of ways. A more control-oriented build may include slower cards such as Lord Godfrey, Twisting Nether, or even Bloodreaver Gul'dan. Slower versions of Mecha'thun Warlock are usually more effective against aggressive decks, but struggle to compete against other faster combo decks. Faster versions of Mecha'thun Warlock often use cards such as Runic Egg to draw out the deck at a faster rate, but are more susceptible to aggressive and midrange decks. Due to its flexibility compared to other Mecha'thun decks, Mecha'thun Warlock can often be hybridized with other Warlock archetypes. Decks such as Handlock and Renolock are fully compatible with Mecha'thun and can use Mecha'thun just as another finisher.
Since all of the combo pieces are even, the deck is sometimes played with Genn Greymane to draw faster with the discounted hero power. Some versions of Mecha'thun Warlock use Supreme Archaeology and Plot Twist, as reducing even one of the combo pieces to zero means that other cost discounts are completely unnecessary.
The simplest method involves playing Mecha'thun, then Cataclysm. Cataclysm clears your board and hand, guaranteeing Mecha'thun's Deathrattle goes off. While this combo was much more practical when Bloodbloom cost 2 mana (thus allowing you to use Cataclysm for two mana less), this is still possible using extra mana discounts such as Emperor Thaurissan with Drakkari Enchanter or Brann Bronzebeard with Galvanizer.
Other methods of triggering Mecha'thun include:
- Play Dollmaster Dorian with Mecha'thun and Kael'thas Sunstrider and a cheap spell in hand, then play Plot Twist. Play the other spell before or after Plot Twist. Afterwards, play Cataclysm for 0 mana. This version of the OTK needs at least 8 mana and all the minion combo pieces aren't destroyed by Hemet, Jungle Hunter.
Mecha'thun Warlock was first introduced alongside it's win condition, Mecha'thun, in The Boomsday Project. At the time, Mecha'thun Warlock had to compete with Mecha'thun Druid, Mecha'thun Priest, and Mecha'thun Warrior. Out of the few decks with Mecha'thun, the combo of Mecha'thun Warlock proved to be effective requiring neither an empty hand nor board to be active. being a semi-competitive deck in both game formats. However, Mecha'thun Druid was more popular and more powerful due to the overall dominance of Druid in the meta and quality of the deck.
Rastakhan's Rumble secured Mecha'thun Druid as the most popular Mecha'thun Deck with the addition of Pounce. That was followed by Mecha'thun Priest, which excelled with the addition of Mass Hysteria. On the other hand, Mecha'thun Warlock received practically no new cards and ceased to be a competitive deck in Standard.
Following Rise of Shadows, Bloodbloom, Cataclysm, Naturalize, and Ticking Abomination rotated into Wild, making Mecha'thun Druid and Mecha'thun Priest Wild only decks. The removal of Blooodbloom and Cataclysm also crippled Mecha'thun Warlock in Standard, which now required playing a 9-mana Mecha'thun in conjunction with Grim Rally, and an empty board, hand, and deck. Mecha'thun Warlock's lost advantage and prevailance of Warrior in Standard meant that Mecha'thun Warrior was the more prominent of the two remaining Mecha'thun decks in Standard.
Saviors of Uldum finally brought Mecha'thun Warlock to a more prominent position in both formats. The release of Supreme Archaeology brought more rewards for drawing cards and Plague of Flames provided more efficient removal. The nerf to Dr. Boom, Mad Genius finally secured Mecha'thun Warlock as the most popular Mecha'thun deck since its creation in The Boomsday Project. In Wild, Mecha'thun Warlock still needed to compete with SN1P-SN4P Warlock, as it provided a both an easier combo and more flexibility. Due to the similarity between the two decks, they often merged as one, providing an extra win condition in the late-game.
Descent of Dragons and the nerf to Echo finally eliminated Mecha'thun Warlock's competitor in Wild, bringing the deck to high popularity. However, Mecha'thun Warlock was still far below the strength of a competitive deck in Standard.
Mecha'thun Warlock moved to Wild in the Year of the Phoenix, along with Mecha'thun. A few weeks into Ashes of Outland, Bloodbloom had its cost increased from 2 to 4. While this change was aimed towards nerfing Darkest Hour, Mecha'thun Warlock was also affected negatively by this change, now requiring more work to discount the combo pieces or alternative means of triggering the combo.
The following cards are played in most or all versions of the deck.
The following Wild cards are played more than occasionally, but not always:
|Common deck types|