The key card is present but its support is thin.
Prioritize useful support such as Summon: Choco/Mog or Loporrit Scout.
Add several Heroes with Aerith Rescue Mission before a Scout attack. With Garnet attacking, removing a Saga’s lore counter can extend future chapters while growing Garnet.
Your deck already enables the plan but is losing the early turns.
Take a castable early creature or efficient answer before a second expensive payoff.
Removing lore counters does not immediately trigger chapters. A Saga already at its final chapter can be sacrificed before combat, so plan Garnet’s attack a turn earlier.
The support is missing
Favor independently useful creatures and interaction if the narrow support does not arrive.