Wail of the Drowned

You summon the souls of those lost to the deep. Choose a point you can see within range. For the spell’s duration, a 30-foot radius centered on that point becomes a churning mass of spectral water. Creatures in the area when the spell is cast or who enter it for the first time on their turn must succeed on a DC 18 Strength saving throw or become Restrained as ghostly hands drag them down. Restrained creatures take 5d10 cold damage at the start of each of their turns. Flying creatures pulled into the area are dragged down 20 feet. The area becomes difficult terrain for all creatures except undead.