Mulligans
How to activate Mecha’thun:
Before your deck has no more than one minions;
Use both Galvanizer to reduce your Mecha’thun to 8 mana.
Save one damage spell that can target your minions (Moonfire, Wraith, or Crystal Power)
Once your deck has no more than one minions;
Play Mecha’thun and then play Baleful Banker to shuffle a copy of it into the deck.
Play Jepetto Joybuzz to get the 1mana 1/1 Mecha’thun and one random minion that in your deck.
Once your board is clear and your deck is empty, your hand should now have only one damage spell and the 1 mana 1/1 Mecha’thun.
Play the 1 mana 1/1 Mecha’thun and play the damage spell on it.
GG you just won your game.