Call of the Deep

Through your bloodline, a curse, or a gift, you have gained the ability to chant a sirens song. You have advantage on performance checks that involve singing.

Also, once per long rest you can attempt to charm all creatures that can hear you, a creature is immune if they are deafened or cannot hear you or immune to being charmed. Creatures must make a Wisdom saving throw against your spell save DC. On a success they are unaffected, on a fail they succumb to your song and must make another save at the start of their next turn. As long as a creature can hear your song, they must make a saving throw at the start of their turn regardless if they have previously succeeded. Your song has the following effects:

• Charmed creatures movement speed is reduced to 10. 
• Creatures must use all their movement walking the most direct path towards you, even through harmful effects.
• A creature cannot take actions, bonus actions, or reactions while charmed.
• Every time a creature takes damage they make a saving throw.
• If you sing while submerged under water, creatures have disadvantage on their saving throws.

You must use your action each turn to continue the song, or it ends. You cannot take reactions nor cast spells while you are singing, and if you take damage you must make a constitution saving throw DC 10 to maintain the song.