Order of the Merchild

Those who have heard the call of the siren have been changed, they often appear as thralls for sirens, usually to lure more to their briney death but there are also those who are able to break free of the call of the siren song and can command these gifts as their own

Aquatic Metamorphosis

When you join this order at 3rd level, you gain some of the powers and abilities of a creature from the deep sea. When you activate your crimson rite you gain the following effects:

• You gain a swimming speed of 40 ft.
• You can now breathe underwater
• You adapt to the pressure of the deep sea, giving you resistance to bludgeoning damage and cold damage.

Call of the Sea

At 3rd Level, as an action you let free a note of a siren's call, forcing all creatures who hear you to be drawn. All creatures within a 40 ft. radius of you and can hear you must make a wisdom saving throw against your Hemocraft Save or become charmed for 1 minute. This charm is unique in that the creature is unable to move. At the end of a charmed creature's turn, they can remake their saving throw. This charm also ends early if you are damaged by an attack. Finally, for every creature you successfully charmed with this ability you gain +1 to your AC (up to a maximum equal to your proficiency bonus). This AC is gone after a short or long rest. This feature can be used once a long rest.

Murky Stalker

At 7th Level, you learn to make the most of an ambush. When you attack an enemy and they are surprised or under the conditions for a rogue's sneak attack (have advantage on the attack or have an ally within 5ft), you can use a reaction and hide immediately. This hide roll gains a bonus equal to a roll of your hemocraft die but you also take necrotic damage equal to the result of that roll. If you are submerged underwater, you become invisible instead.

You can use this feature a number of times equal to your constitution modifier.

Brand of the Circling Fins

Starting at 11th level, your Brand of Castigation makes it easier to close in and circle your prey. When branded, your movement speed changes to that of the branded creatures when you are moving in its direction and gain an addition to that equal to your normal movement speed. (So if your movement speed is 30ft. and your branded creature has 40ft. your movement when moving towards them is 70ft.)

Blood Curse of the Immortal Mermaid

At level 15, you learn to pull upon the powers of the mermaid to grant you life. You gain the Blood Curse of the Immortal Mermaid[1] for your Blood Maledict feature. This doesn’t count against your number of blood curses known.

[1] As a bonus action, you can select a creature within 30 feet of you to make a saving throw using both their wisdom and their constitution saving throws. This roll is made against your Hemocraft save. Should this creature fail, their age increases by 5% and you de-age by one year and heal 2 hitpoints per year you stole. This feature can only be used once a week. Should the creature resist the effect, they are immune to the curse for a year. The minimum age you can regress to in this form is your races mature age.

Amplify. The curse also causes the target to lose hit points by the amount you heal.

Merfolk of the Ocean

At 18th level, your Aquatic Metamorphosis feature is now permanent and instead, you gain the following when you activate your crimson rite:

• You heal 1 hitpoint at the start of your turn if you are below half of your maximum.
• You are immune to bludgeoning and cold damage.