For many generations, Siren has been mistaken as one particular creature. Truth is, all that have been called "Sirens" are actually a multitude of varying humanoid creatures that have been affected by the same thing. All Sirens start normal until they begin noting a strange tone originating always from the open ocean. However, those that seak it come back change in mind and ability, turning into luring predators that nowadays are labelled Sirens.

Siren Abilities.

All Siren's have the following abilities.

Siren's Song. three-action (auditory, mental, primal), Once per day, a Siren can beguile and bewitch with it's song. All creatures in a 60-foot emanation must attempt a Will save against the Siren's Perfomance DC. On subsequent rounds, Siren's can Sustain the song, causing each creature in the area currently affected by your song to attempt another Will save. Creatures of the Siren family are immune to this song.

Critical Success. The target is unaffected and becomes immune to Siren Song for 24 hours.

Success. The target is fascinated with the Siren until the end of your next turn.

Failure. As success, and the target is stupefied 1 for as long as it's fascinated.

Critical Failure. As success, and the target is stupefied 2 for as long as it's fascinated.

Members

Siren Merfolk , Siren Avian

The Voice. No one knows where or what the voice is. Despite retaining some memory and rationality, most that turn Siren have described The Voice as if it was found and not, has an origin yet no origin at all, and having no recollections of searching for The Voice yet clearly changed by something. All that is really known is somewhere, far in the open ocean, something is claiming the humanities of aquan and avian humanoids that have the unfortunate urge to take a listen.

Remnants of the Past. Some Sirens still contain items, including weapons, on their person that they still know how to use. Some items may even hold a clue to where the Siren originated. It's also just as likely that one went out without items or lost them during their confrontation with The Voice. It's completely up to the DM whether to incorporate Sirens equiped or not, just be mindful of the items given to the creatures.