I have finished Dragon Magic, Book Two of Ava Richardson's Deadweed Dragons.
There is an intelligence behind this evil: this Deadweed that hunts the living like tentacles and the Water Wraiths that are a bubbling, drowning, malice. A power, a will, a person far from the South yet seeks to consume them all and has nearly succeeded. Akeem, his Wild Company, and even the Dagfan Training Hall Riders did well, yet it was Dayie and Zarr who turned to the trick. One has heard the phrase "fighting fire with fire", but fighting water with water is a new one on me. Yet the victory is a pyrrhic one, and it will take a witch to fight a witch. A Dragon Witch, to coin a phrase, for Akeem is right: there is none like Dayie in all the Southern Kingdom.