The key card is present but its support is thin.
Prioritize useful support such as Fear of Surveillance or Optimistic Scavenger.
Play Gremlin Tamer or Optimistic Scavenger before casting Grand Entryway. The Room enters as an enchantment, then its unlock trigger creates a separate Glimmer enchantment creature for another eerie event.
Your deck enables the plan but is losing the early turns.
Take a castable early creature or efficient answer before another expensive payoff.
Eerie rewards enchantment entry and fully unlocking a Room, not every partial unlock. Inquisitive Glimmer removes generic costs only, so retain the colored mana for each door.
The support is missing
Favor independently useful creatures and interaction if the narrow support does not arrive.