What counts as a single Ravage when "the next normal Ravage" is affected?

What counts as a single Ravage when "the next normal Ravage" is affected?

A "normal" Ravage refers to the Ravage Actions caused by a single Ravage card during the Ravage Step printed on the board. Similarly the "normal" Build/Explore refers to the Actions caused by a single Build/Explore card during the Build/Explore step printed on the board. (See B&C p. 15 or JE p. 27)
Thus anything modifying the "next normal" Invader Action affects both terrains on a Stage III card, but only one card if there are multiple cards in the slot. It doesn't apply to extra steps added by Adversaries like England, Invader Actions caused by an Event or Power (unless that modifies how the existing card works), or if a normal Invader Step is entirely replaced with a different one by an Event.