Hearthpwn

It's really solid. I stopped playing it because I faced a ton of warlocks with demonic project. However, I managed to beat most other decks because you burn through your deck so fast. 

I don't know if it's T1 but it's a good deck.  It's definitely the best Mecha'thun deck because it's the fastest since it's the only combo that can run Hemet.

I wish I could try it out but I don't have Hemet.

Hmm must have a look..got all the pieces together! Currently working on golden warlock hero though!

from what I've seen it looks surprisingly effective. 5 card combo, which is reasonable, parts of it can be fetched via Dead Ringer. Much like Warlock there isn't much to stop the combo once  it's assembled.

It's probably the only pure combo version of Mecha'thun that can actually work, since Priest has the most efficient stalling tools while also being able to draw really well. The fact that you can build almost your entire deck to be shot by Hemet and the fact that all the combo pieces aren't affected by him makes it really easy to dump your entire deck.

ONly problem I see is that without Duskbreaker it's really easily rushed down by aggro. Zoolock and Odd Rogue are probably the harder counters, especially if they something like Hench CLan Thug or Doubling Imp early.

Zoo decks are the biggest problem I’ve ran into. Your only chance is getting an early Pyro with PWS and other cheap spells. That’ll only work for so long as you need to cycle extremely quickly before you just die. Which is good, because everything else just loses by turn 10-11. 

Yeah, combo decks always struggle against aggro decks. Played today 10 games with mecha'thun priest and lost 8 out of those 10 games because the ladder is full of zoolocks and other fast decks! Also, Hemet was literally the last card in two games, yep. But when you manage to pull off the combo, it's extremely satisfying! 

I wouldn't say that it is Tier 1 since it loses to Demonic Project tech and that 2 mana wraith that increases all minions by 1 mana, but it could be a solid Tier 2 deck I think. Although, it still has solid aggro competition that will really determine if the deck will actually stick in the meta. Odd Rogue, Odd Pally, and Mech Hunter don't seem to be going anywhere any time soon.

Quote from H2050 >>

In tournaments maybe it auto lose to Demonic Project, but definitely viable on Ladder.

 With the prevalence of zoolock, maybe not. 1 Demonic Project to tech against this if it becomes popular is an easy thing to add.  Play on turn 9, easy win.

Quote from lite0 >>

I don't know if it's T1 but it's a good deck.  It's definitely the best Mecha'thun deck because it's the fastest since it's the only combo that can run Hemet.

I wish I could try it out but I don't have Hemet.

 WRONG!  I run a homebrew Druid Mecha'BOOM deck that uses Hemet!

Quote from MrShmoove >>

Quote from lite0 >>

I don't know if it's T1 but it's a good deck.  It's definitely the best Mecha'thun deck because it's the fastest since it's the only combo that can run Hemet.

I wish I could try it out but I don't have Hemet.

 WRONG!  I run a homebrew Druid Mecha'BOOM deck that uses Hemet!

 How do you kill mechathun?  The mechathun druid I used did innervate+naturalize.  Which I guess you could still use hemet in that deck but you'd need the combo cards before you play him which slows it down a bit compared to priest who Hemet on curve.

Thank you for this decklist! It is definitely the most fun deck I have tried so far this expansion.. I think I went 8-1 or something my first time using it. Good luck climbing!