Hearthpwn

This deck is super weak. Losing to every tempo deck  by default. Even any sort of priest with 2x PS.... biggest mistake for me so far is making this deck

I'd reccomend not using Earthen Scales in this deck as its one of the best ways to snooker yourself if you forget you haven't played them as having it only playable on a minion you control makes pulling off the combo impossible if you only have mechathun left. Claw is a much better option as its easy to cycle and gives more options for removal for just abit less armour.

pretty easy if you try to keep his last minion before Mecha'thun stay alive....
either buff his last minion with health stats or freeze him... 
if you buff him, make sure you have enough minion on the board to keep him getting damage from mulling the empty deck. just don't let him die.

since most likely his last 3 cards are Mecha'thun, Innervate, and Naturalize

smart thing to do if your playing this deck is to hold the other Naturalize or a Jasper Spellstone

This thing just killed my Spell Hunter twice!

 (And the weird thing was that my Cybertech Chip drew this Mechathun, too!)