Path of the Modified Body

Necromancy is a frowned upon practice; Self inflicting it is considered heretical or even a perversion of the natural order. You utilize necromancy to alter your form, though fringing the line of transmutation, you use dead body parts of others to enhance your fighting capabilities. You might have attached Tabaxi arms to yourself so you could attack even when you don't have a weapon or apply Aarakocra wings to your back to give yourself flight.

Whatever the case, you turned your body into a walking collection of cadavers and you have learned to use your dangerous mind as weapon onto others who oppose your methods.

Body of Machination

Yours is a path that seeks augment yourself with necromantic or transmutive means, giving you a kinship with constructs. You don’t need to sleep, and magic can’t put you to sleep. 
When you take a long rest, you must spend at least four hours in an inactive, motionless state, rather than sleeping. In this state, you appear inert, but it doesn’t render you unconscious, and you can see and hear as normal. You are also immune to disease.

In addition, when you take a long rest, you can replace either your Body Augmentation, Anatomical Horror, or Physical Modification option so long you have a healer's kit on you. Doing this expends a use of the healer's kit.

Body Augmentation

At 3rd level, when you adopt this path, you choose a body augmentation and gain its feature. This augmentation can look like anything like nodes breaching your skin, exposed bone, or even just a completely new body part replacing what you had before.

Your augmentation might be related to something from your past for example, apart of the augmentation is made by a craftsmen from another part of the world.

Arms

While you’re raging, your reach for your melee attacks is 5 feet greater than normal and your unarmed strikes deal 1d8 + your strength modifier of bludgeoning damage instead of the normal damage. This augmentation grants you larger arms to hit creatures with, you could have added an additional joint to your arms or replaced it with a tendril or the limb of a beast.

Head

While you are raging, you can add your rage damage bonus when you make an Intelligence, Wisdom or Charisma saving throw. This augmentation changes what's between your shoulders, you could have had implanted lead plates into your skull or replaced your scalp with that of a psionic creatures cranium.

Legs

While you’re raging, you can use the Dash action as a bonus action on your turn and you gain the effects of the jump spell. This augmentation makes your legs more nimble, you could have implanted boosters or wings into your thighs or replaced your legs with that of a more nimble creature.

Torso

While raging, you gain temporary hit points at the start of your rage. The temporary hit points equal an amount of D6's equal to your rage bonus. This augmentation could be that you replaced your skin with that of the hide of a powerful beast or you have an arcane device implanted to you that is generating a ward around you.

Anatomical Horror

At 6th level, you gain a magical benefit based on a modification of your choice. You can choose the same body part you selected at 3rd level or a different one.

Arms

Your arms are strong enough to break stone. You gain a burrowing and climbing speed equal to your walking speed.

Head

Your head has a maddening level of awareness. You have blindsight out to a range of 30 feet.

Legs

Your agility is uncanny. Your walking speed increases by 5 feet, you only need to expend 5 feet of movement to make a long jump and no movement is required to make a high jump.

Torso

Your body has unnatural constitution. You no longer require to breathe, drink or eat. In addition, when you expend hit dice on a short rest, you can replace one of your hit die rolls with the maximum number you can roll on that hit die.

Monstrous Physique

At 10th level, you are considered a monstrosity instead of a humanoid and you have advantage on saving throws against spells or magical effects that can change your form, such as the polymorph spell. You also count as one size larger when determining your carrying capacity and the weight you can push, drag, or lift.

Physical Modification

At 14th level, you gain a magical benefit based on a body part of your choice. You can choose the same body part you selected previously or a different one.

Arms

While you’re raging, any Large or smaller creature that is hit with a melee weapon attack made by you must make a Strength saving throw (DC 8 + your Strength bonus + your proficiency bonus) or be knocked prone.

Head

While raging, you have immunity to psychic damage and you cannot be charmed or possessed. In addition when you succeed a saving throw against being frightened you can use your reaction to deal psychic damage to the creature that attempted to frighten you. The psychic damage equals 1d12 + your rage damage bonus.

Legs

While raging, after you successfully hit with an attack using your Reckless attack feature, you can move 10 feet away from that creature and they can not make an opportunity attack during this movement.

Torso

While you’re raging, you can not be stunned.