On T4 Burning-Tree Emissary + Burning-Tree Emissary into Purphoros, God of the Forge results in 5 devotion which means a 6/5 indestructible creature, or on T5 having Purphoros, God of the Forge out and casting Burning-Tree Emissary + Burning-Tree Emissary will deal 4 damage + attacking with a 6/5 means 10 potential damage on t5.

Also, given the right hand, this could easily cast Stormbreath Dragon on T3 and make it monstruos on T4 - dealing around 10-11 dmg ( by himself on T4 )

T1- Rakdos Cackler , T2 - Burning-Tree Emissary into Burning-Tree Emissary , T3 Nykthos, Shrine to Nyx into Stormbreath Dragon )

Shock, Lightning Strike, Magma Jet, Mizzium Mortars and Molten Birth to trigger Young Pyromancer which can trigger Purphoros, God of the Forge.

Chandra's Phoenix and Chandra, Pyromaster for card advantage.