({8} magic symbol) ({2R} magic symbol) ({2R} magic symbol) ({2R} magic symbol) ({2R} magic symbol) at most available.
Steps
Activate
Improvised Arsenal by paying ({4} magic symbol) ({R} magic symbol) , creating a token copy of it. It will enter as a 7/7 Dinosaur due to
Displaced Dinosaurs.
When the
Improvised Arsenal token enters,
Mana Echoes triggers, adding ({C} magic symbol) for each Dinosaur you control.
If needed, activate
Urn of Godfire by paying ({2} magic symbol) , adding ({R} magic symbol) .
Repeat.
Notes
The mana cost can be reduced if you control more Dinosaurs as the combo begins. You should perform step 3 only if you have no ({R} magic symbol) in your mana pool.