The creature can gain a sacred bonus to its AC when on any good aligned plane.
Benefit: When on a good-aligned outer plane, the creature can imbue itself with a portion of the plane as a full-round action. This grants it a sacred bonus to its AC equal to its Charisma bonus. The sacred bonus lasts for a number of rounds equal to the creature’s Charisma bonus. This feat can be used three times per day. This feat can only be taken once. For example, a solar on a good-aligned plane spends a full-round action using this feat. It gains a +7 sacred bonus to its Armor Class that lasts for 7 rounds.
Tome of Horrors Complete, Copyright 2011, Necromancer Games, Inc., published and distributed by Frog God Games.