Geomancer ability: Quaking Word

By thejoker, in Descent: Journeys in the Dark

Hello i have a question about the ability Quaking Word

the card says " Perform an attack with a magic weapon . This attack gains : with a surge each monster figure within 2 spaces of a Summoned Stone tests awareness. Each figure that fails is stunned.

if the geomancer have more than one summoned stone on the map, he has to choose one of his summoned stone or each summoned stone gain the effect?

Thank you

Each stone gains the effect.