Waters of Aquarius

You conjure the spectral form of Aquarius the water bearer within range. Aquarius appears as a gargantuan humanoid carrying a massive amphora, which he immediately turns upright, emptying its contents. The water forms an area can be up to 50 feet long, up to 15 feet wide, and up to 20 feet tall. Each creature in that area must make a Dexterity saving throw. On a failed save, a creature takes 5d10 bludgeoning damage and is washed away knocking it prone. On a successful save, a creature takes half as much damage and isn’t knocked prone. The water then spreads out across the ground in all directions, extinguishing unprotected flames in its area and within 100 feet of it, and then it vanishes.