The creature can gain a profane bonus to its AC when on any evil aligned plane.
Benefit: When on an evil-aligned outer plane, the creature can imbue itself with a portion of the plane as a full-round action. This grants it a profane bonus to its AC equal to its Charisma bonus. The profane 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 pit fiend on an evil-aligned plane spends a full-round action using this feat. It gains a +8 profane bonus to its Armor Class that lasts for 8 rounds.