Self-Concealment( Epic Level Handbook, p. 66)
When in combat, your form becomes blurry and indistinct, making it difficult to land a blow against you.
Attacks against you have a 10% miss chance (the equivalent of one-quarter concealment). You lose this benefit whenever you would lose your Dexterity bonus to AC.
This feat may be taken multiple times. Each time it is taken, the miss chance increases by 10% to a maximum of 50% after it has been taken five times.