From the back cover
Woe to the enemies of heaven!
Avatars are the mortal agents of the Heavenly Host summoning down the wrath of Heaven on the Unholy. They cast divine spells like clerics, but specialize in the summoning of celestials and can even take on angelic forms at higher levels. The Avatar's Handbook introduces this new core class to the d20 System and gives yoiu all the rules you need to incorporate it into your campaign. Fourth in the acclaimed, Master Class series, the Avatar's Handbook includes:
25 new celestials
7 additional creatures from the Upper Planes
5 new templates, including the reforged and the uncalled.
2 sample Archangels
21 new spells for divine casters
Complete compatibility with Legions of Hell, Amries of the Abyss and Book of the Righteous.