How does "+1 Damage with Damage-dealing Powers" (e.g., Flame's Fury) work? What exactly does it increase?

How does "+1 Damage with Damage-dealing Powers" (e.g., Flame's Fury) work? What exactly does it increase?

For every power that does Damage, it increases one part of that Damage by 1.
For instance, if a power does "1 damage to each Invader", Flame's Fury would let you do 2 damage to one of those Invaders. If a power does "1 Damage to each Town/City", Flame's Fury would let you do 2 damage to one of the Towns or Cities. If a power does "1 Damage to 1 Town/City", then Flame's Fury would let you do 2 Damage to 1 Town/City. If a power does "1 damage" and then (with another condition) another "1 damage", then you deal a total of 3 damage. If a power does damage in multiple different lands, you only get the bonus in one of the lands. If a power ends up doing no damage at all for some reason, then you do not get a damage bonus.
You only get the bonus once per use of a damage-dealing power. If you use a Power multiple times by Repeating it, or if a Power sets up a triggered action that is triggered more than once, the bonus applies each time.