Most Vessels are usually Lawful Good, True Neutral, or Chaotic Evil, any others are nearly unheard of and very uncommon.

Vessels know a small range of languages ontop of their own, these are-

Hollow Speech, Deep Speech, Common, and Abyssal, however they are unable to verbally talk, and can only talk telepathically to any number of being within 120 feet of them. 

You know a cantrip only known by other Vessels, however it is near the likes of Vicious Mockery.

Hollow Speech
Enchantment
Cantrip
Casting Time: I action
Range: 120 feet
Components: V
Duration: Instantaneous
You speak your native language to a being in range of your telepathic speech and you can see, (does not need to understand you), it must succeed on a Constitution saving throw (8+Con+Prof) or take Id4 psychic damage and have disadvantage on the next attack roll it makes before the end of its next turn. (add 1d4 every 4 levels after level 1)

You know the Light Cantrip.

Never get lost as if you were an Outlander, however you do not need the Outlander Background.

You have a very strong carapace, if you are unarmored it gives you resistance to Fall Damage, you take no fall damage anywhere under 30 feet, and you have resistance to Force and Bludgeoning damage but are vulnerable to Cold damage, your unarmored AC is 10+Con+Dex (does not stack with barbarian unarmored defense).

Vessels are old beings, they can live anywhere from 200-900 years old, and are unable to die from old age, or being fully turned to ash., however they do require 24 hours of rest before being able to fight if they would "die" in a battle. 

Cost 1 Soul Charge-, You send Soul Charge through a Dagger and slash through any being, willing or unwilling, and know what they are thinking at the moment, this does no damage.

Increase your Dexterity by 1 and Constitution by 2.

See up to 60 feet in darkness as if it was dim lighting.

You are between 2-4 feet tall not counting your horns and anywhere from 40-90 lbs, your size is small, and you have 25 ft of moment on land and 20 flying movement at level 3.

Every Long Rest, take only 30 minutes instead of the full time, gain the same benefits of a long rest and gain 5 Soul Charge. 

A small rapier like weapon, that is finesse, dealing piercing or slashing damage, this can be Magical or Non magical and deals 1d8 + Con with a range of 10 Feet after level 5. This weapon can not be held by any race other than a Vessel.

When you hit with your Nail you gain 1 Soul Charge up to 10 total, you can use Soul Charges for multiple things. Hitting a critical or vulnerable attack gives 2 Charges. 

Using one hand you can jump onto a wall and jump off upwards to move up the wall equal to your movement speed (does not take movement speed to do this after 5th level, learn at 3rd level)

Costs 5 Soul Charge, If you get within 5 feet of the target, you can jump up and slam your small body with a magic force into an enemy dealing xd4 force damage, x= your level. Add Con mod to attack roll.

Costs 2 Soul Charge,--Con Save of 8+Con+Prof--30 feet in front of you, you may shoot magical Force/ -Radiant or Necrotic Damage (you pick) of 1d6 + Con, if you hit an ally with this they heal that much instead.

Costs 1 Soul Charge, heal 1d4+Con+Prof (Raise to 1d6 at level 5 and 1d8 at level 10)

As a reaction or on your turn to avoid an attack/disengage you can dash back 20 feet if there is room without provoking attack of opportunity, you may only do this if you did not use your dash the previous turn.  (Learn at 3rd level)