These are Soul Eaters. A demonic like fighter that literally eats the souls of their enemies for breakfast. They are strong, fast, and cunning. They are natural killers that live to feast on the souls of their victims. This doesn't mean they are all bad though, they make for great defensive partners and investigators. They can be some of the nicest and most helpful people you can know. These people know how to wield the souls of other people and their own. They are dangerous if you make them mad but can be a huge asset if a friend.

Soul feast

Starting at third level you have master the art of eating souls. You can eat a soul of any creature within 5 feet of you that has been dead for less than a day. When doing so, you get to choose a ability of your choosing (Strength, Dexterity, Constitution, Intelligence, Charisma, and Wisdom) and add that creature's ability bonus to yours for 1 minute. If you eat a soul within a minute of eating another soul, your added ability bonus is replaced with the new one. You cannot eat the soul of one creature more than once.

When you eat a soul, that counts for half a day's rations.

(You will have to keep track of ability bonus's on your own due to dndbeyond not having an option to have that modified)

Soul Sense

Due to your hunger for souls, you can passively sense the souls of bodies that have been dead for less than a day within 200 ft of you. If you role high enough on a perception role, you can sense souls of bodies that have been dead for less than a day within 1 mile of you.

Soul Enhancment

You may spend your bonus action to course your soul through a weapon you are holding to enhance its properties. When this is done your weapon does an additional 1d8+2 necrotic damage starting at 7th level. This effect only lasts for 1 minute.

The enhancement increases by 1d8 every 10th level (2d8+2), 13th level (3d8+2), 16th level (4d8+2), and 19th level (5d8+2).

You can do this once per a short rest.

Soul Weapon

At 10th level you can use your action to summon your soul as a weapon. This cannot be done if you are using your soul to enhance a weapon at that time and vice versa.

When you summon your soul into a weapon you summon your soul into the shape of a sword within 30 feet of you, after you do this you can make a melee spell attack against a target of your choice within 5 feet of the sword. On a hit, the target takes 1d10+10 necrotic damage. Until the spell ends, you can use a bonus action on each of your turns to move the sword up to 30 feet to a spot you can see and repeat this attack against the same target or a different one.

This spells damage increases by 1d10 at 15th level.

This spell lasts for 1 minute.

You can do this once per a short rest.

Soul Animal

At 15th level you can use your action to summon your soul as your soul animal for 1 hour. Pick a creature with a challenge rating of 10 or below, your soul animal uses that animal stat block for its own. If you soul animal's HP drops to 0 it goes away and you are paralyzed for 2 turns and gain a point of madness. This can not be done if you are using your soul to enhance a weapon or using your soul as a weapon, and vice versa.

You can summon your soul animal once per a long rest.

Soul Crusher

At 18th level you can spend a whole turn (can not be used if you have moved, used an action, bonus action, etc.) to disrupt the souls of all hostile creatures within 60 feet of you.

All creatures effected must role a Constitution saving throw with a DC of 25. If a creature fails the saving throw they take 10d8+5 of psychic damage and are paralyzed for 1 turn, after the paralysis effect is done they must role a Wisdom saving throw with a DC of 20 or fear you for 3 turns. If a creature succeeds in the saving throw they take half of the damage and is paralyzed for 1 turn. This causes one point of exhaustion and madness after use.

This can be used once every long rest.