Helike

Helike is a Sea Harpy  from The Siren Sea where she lives with her partner Agamede and her five children Ligeia, Leontios, Thetis, Viola and Phaia. 
Helike is an oracle of Thassa who has recently bestowed her with a secret quest to travel Theros in search of answers to recent mysterious occurrences. Thassa has forbidden Helike from revealing her quest - causing lungs to fill with saltwater if she attempts to speak of Thassa's secrets. This has led to some conflict within Helike's family, many of whom are confused and hurt by her sudden apparent abandonment. Agamede suspects Helike has gone to retrieve her wayward daughter Ligeia who recently eloped with a Human bard she rescued from drowning.