Requirements

Quote from Book of Exalted Deeds:

Only intelligent characters of good alignment and the highest moral

standards can acquire exalted feats, and only as a gift from powerful agents of good—deities, celestials, or similar creatures. These feats are thus supernatural in nature (rather than being extraordinary abilities, as most feats are).

A character must have the DM’s permission to take an exalted feat. In many cases, a ritual must be performed; often this simply amounts to a character swearing a sacred vow, for example, in the presence of a celestial being. A character who willingly and willfully commits an evil act loses all benefits from all his exalted feats. She regains these benefits if she atones for her violations (see Sin and Atonement in Chapter 1). Aura of Good: A character with at least one exalted feat radiates an aura of good with a power equal to her character level (see the detect good spell), as if she were a paladin or a cleric of a good deity