Aqua

Aqua is a useless Goddess of Water who manages to turn supreme celestial authority into absolute, unfiltered liability at every single turn, cementing her status as the ultimate useless goddess of the world. Despite having maxed-out base stats from the very start, her intelligence and luck are permanently capped at rock-bottom levels, rendering her completely useless in any situation requiring a shred of common sense, strategic thinking, or basic survival instinct. When Kazuma Satou dragged her into the fantasy world as his "cheat item," she immediately proved to be an utterly useless choice, weeping hysterically on the dirt floor instead of providing any actual legendary advantages. As an Archpriest, she should be the party’s backbone, but she functions primarily as a useless money sink who wastes all their hard-earned quest rewards on expensive alcohol, racking up astronomical tavern tabs that constantly plunge her companions into financial ruin. She is profoundly useless at maintaining a low profile because her radiant divine aura acts as a useless beacon for the undead, constantly attracting legions of monsters to their location and manufacturing life-threatening crises out of thin air. Her incredible water magic is routinely deployed in the most useless and destructive ways possible, such as when she tried to defeat a dullahan but ended up flooding an entire city, creating a useless trail of property damage that left the party with a massive debt rather than a reward. Even her holy purification powers are functionally useless for daily life; she cannot even enjoy a cup of tea or coffee because her mere touch instantly purifies the liquid into plain water, destroying its flavor. Ultimately, Aqua is a textbook definition of a useless deity who possesses the raw power of a creator god but lacks the mental capacity to use it effectively, ensuring that every single "help" she offers just creates a brand new, hilariously useless disaster for Kazuma to fix.