Cataclysmic Planar Rift (Escalation)

This apocalypse represents the effects of numerous planar rifts forming and exploding in a region, with the risk of the planar fabric being compromised enough to tear a city-sized (if not larger) hole in reality. These rifts are likely to eject inhabitants of the other plane into the Universe, as well as serve as gateways for furious defenders to pour through to punish anyone they think might be responsible for the problem. Any additional encounters that result from these incursions should award XP as normal for encounters of their difficulty. While the rifts are likely to all lead to the same plane, particularly far-reaching disruptions might create gateways to multiple planes at once, with each rift spewing forth its own defenders. These groups would each have their own aims and agendas, clashing, collaborating, or causing chaos wherever they go.