Here's the write up of a Radiant Idol's abilities from the 3.X Wiki:
Radiant idols maintain most of the same abilities they had as angels. They have a wide array of spell-like abilities, have the ability to regenerate their wounds, and are immortal. All radiant idols are immune to acid, cold, and petrification, and all angels are highly resistant to electricity and fire. Radiant idols have darkvision, low-light vision, and the ability to speak any language. Like angels, radiant idols are surrounded by an aura; however, this aura has been corrupted, and it now inspires fear and awe in mortals around them.
Radiant idols will work specific magics upon those that worship them. They can perform a ritual of initiation, which they call the Blood Oath. This ties the worshiper to the radiant idol through magical and mental means. The ritual itself lasts for 2 hours, and afterwards, the radiant idol and its subject are mentally bonded. This allows the radiant idol to mentally communicate, locale, scry upon, torture, or even kill the worshiper. These abilities know no distance limit. Those successfully subjected to the ritual are enthralled by the idol, following their every word. There is no limit to the amount of people that a radiant idol can subject to the Blood Oath.
As part of their banishment from Syrania, radiant idols are also subjected to a curse when their wings are removed. Radiant idols cannot fly by any means, including magical ones. Any spells that grant flight to other creatures automatically fail when cast upon a radiant idol, and any magical effects that cause flight will fail within 30 feet of the radiant idol.