"The readings are off the charts! Whatever it is, it's close."

Entity Tracker

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Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, draw a card.

Duskmourn: House of Horror

An ability that triggers "whenever you fully unlock a Room" triggers when a door becomes unlocked and the other door of that Room is already unlocked, or when both doors of that Room become unlocked simultaneously.

If a permanent with an eerie ability enters at the same time as one or more enchantments, its ability will trigger for each of those enchantments.