Mithril chain of shadows

This fine suit of armor is lined with black velvet. When worn by a thief, it improves hide in sneak chances by 5 and makes a thief 50% likely to be invisible in near darkness (even to infravision). It can also be used to cast darkness, darkness 15' radius, and continual darkness once each per day (at 12th level of magic use). Finally, once per day a wearer can actually transform into a shadow for up to 12 turns, becoming a shadow in all respects save for mental ones (thus, a wearer cannot be damaged by nonmagical weapons, and undead take the wearer for a shadow and ignore him or her). Saves against light-based attacks (for example, a light spell cast into the eyes) are always made at +2 by a wearer of shadowcloak armor.
If a priest successfully makes a turning attempt against the wearer in shadow form, the cloak wearer is permitted a saving throw (this is at +4 if the priest is actually able to destroy shadows). If the save fails, a wearer suffers 1d6 points of damage per level of the priest and the armor is destroyed. If the save is made, a character takes half damage and must flee in fear at maximum rate for one turn.
Bonus to AC: +2