The key card is present but its support is thin.
Prioritize useful support such as Elementalist Adept or Burst Lightning.
Develop Balmor and another creature before spending Burst Lightning to clear a blocker. The cast trigger pumps the team before the damage spell resolves, allowing a stronger trample attack.
Your deck enables the plan but is losing the early turns.
Take a castable early creature or efficient answer before another expensive payoff.
Balmor requires an instant or sorcery, while prowess accepts any noncreature spell. Too many tricks without creatures leave both rewards ineffective, and a creature spell never triggers prowess.
The support is missing
Favor independently useful creatures and interaction if the narrow support does not arrive.