Idyllglen

Idyllglen was a village in the forgotten realms. It's location is unknown, but it is assumed that it is near Baldur's Gate.

Zariel

The only known event in Idyllglen is Zariel's betrayal. Yeenoghu had sent an army to fight in the blood war, which spilled into the material plane. Zariel took an army of Hellriders to fight the demons. Zariel was then betrayed by Jander Sunstar and other knights. Zariel led her loyal servants into Avernus to continue the battle, but the traitors fled. She was left trapped in Avernus, to be transformed into an archdevil by Asmodeus and ruled Avernus from then on. [1]

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