Mulligans
General Mulligans
Definitely keep the mechs, shadow visions if you need a combo piece and keep the other spells, we're going for a t4 or 5 win!
I theorycrafted Inner Fire Priest for the Boomsday Project. I’m not sure about the Injured Blademasters, but the Test Subject will be able to be buffed, traded and healed for cycling, card advantage and cheap hero healing. The mechs are the bread and butter of the combo, the first few turns would ideally be:
T2: Unpowered Mauler/Upgradeable Framebot
T3: Bronze Gatekeeper on either of those minions
T4: Double Divine Spirit and Topsy Turvy for a 36-40 Damage OTK with room left over in hand for a Silence if you need it.
These games should be decided early but if they start to stick minions to the board, you can use Mass Dispel and buffs for swing damage to close it out.