The key card is present but its support is thin.
Prioritize useful support such as Healer's Hawk or Strix Lookout.
Play cheap flyers before Empyrean Eagle so its bonus changes the next attack immediately. Strix Lookout can attack with vigilance and then loot if you have spare mana and do not need it untapped.
Your deck enables the plan but is losing the early turns.
Take a castable early creature or efficient answer before another expensive payoff.
A deck of small flyers still needs a way to survive larger ground attackers. Do not assume Eagle improves itself or that a low-toughness flyer survives combat after Eagle is removed.
The support is missing
Favor independently useful creatures and interaction if the narrow support does not arrive.