Tail and Tentacles | The Little Mermaid Retelling

A full human, a half- octopus, and a half fish.

Up the sea waters, the mermaid princess, Ember, with a new pair of human legs, continues her expedition to find the man responsible for all the sacrifices she had come across from venturing the land. When opportunity swam across him, Serafino, a Cecaelia-half-octopus race, and is bound to be only the second best between his brother, desired to prove his worth by keeping a close contact to the princess, which their kind believed to be Cecaelia's sworn nemesis. Ensuring she will never return back to her original form, he fixes his mind to accomplish his goal, but the lapping savage waves of the sea become gentle as the soothing wind blows a human that will make each of their hidden missions easier.

Three different species.
Two undisclosed motives.
One friendship?