Given that this has a reliable way to get Mecha’Thun on the board and fulfill 2/3 of his conditions in a single turn (Galvanizer –> Mecha’Thun, Galvanizer –> Mecha’Thun, Mecha’Thun, Bloodbloom, Cataclysm) as well as being a decent deck on its own with lots of stalling methods, I’d say this is the most reliable Mecha’Thun deck I’ve seen so far.
Given that this has a reliable way to get Mecha’Thun on the board and fulfill 2/3 of his conditions in a single turn (Galvanizer –> Mecha’Thun, Galvanizer –> Mecha’Thun, Mecha’Thun, Bloodbloom, Cataclysm) as well as being a decent deck on its own with lots of stalling methods, I’d say this is the most reliable Mecha’Thun deck I’ve seen so far.