Mulligans
General Mulligans
Getting Heropower damage in while drawing as much as possible is the plan. FInishing step 1 of the combo asap really reduces the number of cards that get stuck in your hand because they're part of the combo. So keeping hatchlings, simulacrums, Jan'alai, or pipers off the mulligan is a good call. Other than that, mulligan away other combo pieces and focus on draw cards.
The combo has 4 steps:
1. Play both simulacrums with Helpless Hatchling in hand. Play all Helpless Hatchlings and kill them with Jan’Alai in hand. Jan’Alai now costs 3.
2. Play Thaurissan with Jan’Alai, Drakkari, both Molten Reflections in-hand.
3. Over the course of the game, deal 8 damage with your hero power.
4. Play Jan’Alai for 2 mana, Drakkari for 2 mana, and both Molten Reflections on the Ragnaros you summoned. Deal 8 damage 6 times. Laugh gleefully as one of the worst combos ever kills your opponent.
The card picks not associated with the combo are mostly draw cards and some utility.