In this case I am talking about a specific scenario involving the following feat and power combo.
I have a level 9 Invoker who has Mark of Storm:
Mark of Storm [Dragonmark]
Benefit: Whenever you hit an enemy with a thunder or lightning power, you can slide that enemy 1 square.
I am considering taking the L9 Invoker Daily, Herald of the Storm Unleashed, which has the following:
Effect: The burst creates a zone of lightning and thunder that lasts until the end of your next turn. Any creature that begins its turn within the zone takes 5 lightning damage. Any creature that leaves the zone takes 5 thunder damage. As a move action, you can move the zone 5 squares.
Would creatures starting in or leaving the zone be subject to the slide granted by Mark of Storm?