Champions of the Titan's Eye
At the beginning, the party only knew they were framed for the murder of some of their brethren. What they have found out since, via The Enchantress, is that they did indeed destroy a host of angels.
The Fallen Champions were once known as angelic warriors of the light, cleansing the world of demons and their kin. In a foolish move, they made a deal with Graz’zt to protect his favored mortals and focus on other demons, and in return they would receive the favor of the Dark Prince. Of course, this kind of favor is powerful but corrupting.
As the party (then angels) assailed a mortal Temple of Graz’zt, the Fallen Champions intercepted and fought in the temple’s defense. Seeing that their brethren had been corrupted, the party won a tough battle and destroyed each Fallen Champion, ridding the world of their dark influence…
But for some reason, no one else knew the fallen were corrupted, and they did know the party destroyed them. So, the party was imprisoned.
As of Session 4, the party also knew the names and a brief description of each fallen champion: