This campaign is a single story, which is spread across different eras, game systems, and cosmologies. It is literally a campaign twenty years in the making.
Dungeons and Dragons: Kalamar (Godwar) – Epic Level (Fury of the Elements)
Mutants and Masterminds: (Fight Fire With Fire) – (Between the Shadows)
Pathfinder RPG: (Sins of Past and Present)
Primal Order/New Gods: (Senate of Sentients)
TORG D6: (Second Invasion)