No one knows for sure what happened. Some blame the demons and devils, some blame the gods, and the coalition blames magic use, but the truth is that no one knows for sure.
Whatever the cause, one day gates the Ley Lines surged. Their color changed from blue to red, and gates opened at every nexus point. Demons, devils, dragons, angels, and any other nightmare imaginable spewed forth onto the material plane. This caused severe weather disruption, earth quakes , tidal waves, and lightning storms which killed off at least half of the world population in a matter of days.
After a week, things were stable, except of course for the rampaging monsters…