Aqueous Formutility$0.40A one-mana Aura that makes a creature effectively unblockable and adds card selection whenever it attacks. It fills the same evasive role while providing extra value.
Whispersilk Cloakprotection$2.74Grants unblockable like Cloak of Mists and also protects the creature from targeted removal. It is a stronger but much more expensive equipment version of the same evasion effect.
Wonderutility$1.99Gives your creatures flying from the graveyard, often functioning as evasion for blue decks. It is not a direct Aura replacement, but serves a similar unblockability-adjacent combat role.
Shadow Riftutility$1.66A cheap blue spell that makes a creature essentially unblockable for a turn, closely matching the combat function. It is more temporary but can also replace itself with a card draw.
Slip Through Spaceutility$11.23A cantrip that grants unblockability for the turn, making it a very close functional alternative for pushing damage through. It is cheaper and replaces itself.
Artful Dodgeutility$0.52Can give a creature unblockable for a turn and has flashback for repeat use. It is more flexible over time, though not a permanent Aura.
Trailblazer's Bootsutility$2.37Often makes a creature effectively unblockable in Commander by granting nonbasic landwalk. It is a colorless equipment analog to an evasion Aura.
Fear of Impostorsutility$0.22A blue enchantment creature that can help make combat awkward and push damage through by limiting blocks in its own way. It is not identical, but it occupies a similar evasive blue role.