(This is a provisional answer – if further cases like this suggest that "Effects expire" needs to be an action, it could conceivably change, but that seems the less likely case.) Tags: Actions, Action Modifiers, Rulings Under Examination, Heal, 10 more...
The damage from destroying your Presence is part of the same action because the Special Rule says "When you destroy your Presence..." – it modifies how other actions work while they're happening. Tags: Destroy, Saved From Destruction, Action Modifiers, Damage, 25 more...
This can happen with "Flowing and Silent Forms Dart" by in concert with anything that adds Blight one after another in multiple lands, like cascades or Volcano's "Explosive Eruption". Tags: Destroy, Saved From Destruction, Blight, Presence, 8 more...