I thought that Avacyn was going to be a world, but it looks like Avacyn Restored is a M:tG card set based in Innistrad. So it might be worth looking at, alongside Plane Shift: Innistrad and A Planeswalker's Guide to Innistrad.A Planeswalker's Guide to Avacyn Restored wrote:During Avacyn's absence, the angels suffered. Without their leader, the flights became disorganized and ineffectual. Many retreated from view, lost without the power that created them. Avacyn's disappearance took a toll on the Lofts, the holy site above the Thraben Cathedral where Avacyn dwelled with her hosts of angels. From the outside, the Lofts appear to be a long attic tucked under the eaves. But once inside, the space is much larger than it appears to outsiders. None but the angels are permitted to enter the Lofts. Because of this, there was no outside witness to the dramatic deterioration of the space during Avacyn's absence. Before, it was an elegant hall in pristine condition. But the hall literally crumbled without the archangel, until rubble covered the flagstones and rain fell through the gaping holes in the roof.
Gisela, the leader of Flight Goldnight, was devastated in the aftermath of Avacyn's disappearance. Gisela was one of the few witnesses to the battle between Avacyn and Griselbrand. She had been the archangel's confidant, closest ally, and strongest sword. And when she watched Griselbrand strike Avacyn with a killing blow and trap her in the Helvault, Gisela experienced emotions she'd never felt before: fear, helplessness, and despair.
When the Helvault shattered, Avacyn emerged at her full strength. Her presence infused the Avacynian protective wards with holy magic once again. The angelic host was restored to its full power, which gave the humans the chance to gain the upper hand in their fight against evil. The three flights of angels reformed in greater numbers than before. Once again, they became Avacyn's soldiers on the front lines of battle. Only this time, instead of barely containing the monsters of the world, the angels and their human allies began pushing them back, away from the bastions of human civilization. For the first time, they were winning.
I guess that the return of Avacyn (or the disappearance of Avacyn) would be a potentially interesting plot point in an Innistrad campaign. But there might be some mutually exclusive things between the different Planeswalker's Guides and the Plane Shift document.
Anyhoo, here are the parts of A Planeswalker's Guide to Avacyn Restored:
- Planeswalker's Guide to Avacyn Restored: Part 1 - Introduction, Flights of Angels (Flight Alabaster, Flight Goldnight, Flight of Herons), Avacynian Archmages (Archmages of Goldnight, Archmages of Alabaster, Archmages of Herons), Gryffs and Gryff-Riders, New Evil Arises
- Planeswalker's Guide to Avacyn Restored: Part 2 - Cathar Masteries, Gavony Riders, Moor Chaplains, Mausoleum Guards, Keepers of the Pale, Lunar-Smiths, Diabolists, Nightfall Duelists, The Quiver of Kessig, Gatstaf and the Cursemute, Avacyn's Gift, Liliana Vess and Garruk Wildspeaker