Choose a spell-like ability you possess or a spell you can cast. You gain the benefits of this magic whenever it is used near you.
Prerequisites: Spellcraft 24 ranks, caster level 12th.
Benefit: Choose a spell-like ability the character knows, or a spell the character can cast. The character is attuned to the magic he or she chooses. If another spellcaster within 300 feet of the character uses this magic, the character also immediately gains the magic’s effect as if it had been used on the character by the same caster. The character must have direct line of effect to the spellcaster in order to gain the benefit of the attuned magic (though the character does not have to know the spellcaster is present, and he or she can be flat-footed). The magic’s duration, effect, and other specifics are determined by its original caster’s level.
Special: A character can gain this feat multiple times. Its effects do not stack. Each time a character takes the feat, it applies to a different spell or spell-like ability.
Source: Standard Reference Document under Open Game License v1.0a, which updated this feat originally published in the Epic Level Handbook, page 67.