Curiosityutility$0.63A cheap blue aura that enhances a creature, but instead of power/toughness it turns combat damage into card draw. It fills a similar low-cost enchantment-on-creature role in blue.
Triton Tacticsprotection$0.15A blue combat trick that can protect or enable an attacker at very low cost. Like River's Favor, it is a cheap blue way to improve a creature temporarily.
Aqueous Formutility$0.40A 1-mana blue aura that upgrades a creature with evasive value rather than raw stats. It occupies the same cheap blue enchantment slot as River's Favor.
Flightutility$0.12A classic blue aura at the same cost that grants a creature a new combat ability. It serves a similar simple creature-enhancement role.
Artful Dodgeutility$0.52A low-cost blue spell that helps a creature connect in combat. It is not an Aura, but it plays a similar role as a cheap blue combat enhancer.
Spectral Flightutility$0.12A 2-mana blue Aura that boosts a creature and adds flying, making it a stronger version of a cheap creature enhancer. It is a clear functional upgrade in the same color.
Spire Golemutility$0.22Not an Aura, but it is a blue creature that functions as an efficient board presence at a low mana investment. If you want a simple blue tempo booster, this is a practical equivalent in deck role.
Vapor Snagutility$0.26A cheap blue tempo spell that can swing combat by removing a blocker or pushing damage through. It overlaps with River's Favor as a low-cost blue way to influence a creature battle.