Praxis Storm (Brewers Ball: GO BIG)

Mulligan for a merchant + influence (having a card draw effect is good too)

Play random units and powers in the early game. Market for Rebuild.

Once you have either played all of your fire sources (Ideally 7+), or you are scared of dying, play Rebuild. Use any +power and +cards effects. Hopefully you can immediately redraw the destiny Rebuild.

After that use Excavate and Lumen Attendant to redraw the destiny Rebuild (or other cards depending on what you need)

Generate lots of power and draw lots of cards.
Eventually either play a double-damage Flash Fire, or use one of the draw-from-void effects to redraw Flash Fire so that you can play it a second time.

Notes:
Demand Death and Lumen Attendant play units, which makes Harmony of Flame more effective.
Turn Back Time makes the card voidbound. You can use it on Rebuild, but do other redraw effects first, or use it on a different card.
Wrath of Caiphus breaks the opponent's aegis.
Glimpse the Possibilities is sort-of like card draw on a combo turn.
Demand Death gives you until the end of the next turn, so you can Flash Fire on the first turn and redraw and replay it on the second turn.
Don't rush to get Flash Fire, just focus on generating power and drawing cards. Shavka Evangel, Demand Death, and Harmony of Flame make it easier to keep the combo going once you get started.