Hearthpwn

1. Draw like your life depends on it

tap, Sense Demons, Bloodmage Thalnos

2. Wild is a place where people cheat

Cheat out your huge threats thx to Voidcaller

3. Heal if needed

After you are out of duplicates thx to hero tap and Sense Demons - heal with Reno Jackson

4. Look! I can spam board with crap too!

Swarm board again and again with Bloodreaver Gul'dan and N'Zoth, the Corruptor

5. Prepare the combo

Discount your Mecha'thun+Bloodbloom combo for 2 mana so that you could use them together when you have 10 mana with Galvanizer and Emperor Thaurissan

6. Accelerate the draw

When you are getting closer to combo and already drew your vital pieces use The Soularium, especially good if you are missing Galvanizer/ Emperor Thaurissan as you can play them the same turn avoiding discard of vital pieces

7. Combo 

when you are out of cards in your deck Mecha'thun+Bloodbloom+Cataclysm

The Soularium is totally insane in this deck

1) You are desperate and beaten down in corner by extreme aggro and have and least 7 mana, use The Soularium you may pull Reno Jackson or missing duplicate

2) You have the combo but miss your discount cards and is at 9 or more mana

3) You got lucky and managed to get 3 mana discount for the combo and have 3 cards left in the deck, guess what...