Siren-Patron

Your character has traded a heart of a loved one for the knowledge and the magic Sirens possess. These deals are normally with women as men normally fall prey to sirens as they are vulnerable to their magic.

Aquatic Accustoms

You are now used to the lifestyle of the oceanic life. You can communicate with aquatic creatures and water elementals, but they can only respond with simple sentences. Swimming speed will be improved to double the user's walking speed, as the user finds themselves naturally be propelled in the water by some strange magical force. The user is also granted the ability to breathe in salt water for 6 hours at a time, you are granted half the time in other bodies of water simple aquatic life are able to live in.

When swimming, creatures around you must make a DC 10 Dexterity saving throw, as your swimming creates strong undercurrents that can put the creature off balance. Causing the creature to be tossed into a random direction and take 3d6 bludgeoning damage. 

Siren teachings

Starting at level 1, are now immune to being deafened and have an advantage on sound-based skill checks as well as proficiency in the passive perception of sounds.

As a reaction action to getting damaged, you can warp 30ft in a puff of seafoam. This is once per short rest.

Siren Sounds

At level 6, one per long rest you can channel the calling of your patron. Any hostile enemies of the opposite sex who hear your call will switch targets to you 300ft, as they do this they have a disadvantage to saving throws to anyone beside you. This enchantment lasts for 7 turns and requires concentration, when you break concentration the enchantment stops working. When the enchantment stops, the victims will continue on like they had no memories of the ordeal.

Horrific Harmony

Starting at the 14th level, when you hit a creature with an attack, you can use this feature to initiate psychological warfare. The target will fall into a semi-conscious state, cannot attack but can still doge attacks (only at disadvantage).

At the end of your next turn, the target returns to normal (kinda) . If the target is not a siren, it takes 10d10 psychic damage as it reels from its horrific experience.

Once you use this feature, you can’t use it again until you finish a long rest.