You may feed upon flesh to sustain your own strength. As an action, you can "eat" a corpse, healing for 1d8 + your Constitution modifier. You may use this trait a number of times per day equal to your Constitution Modifier + proficiency bonus and is restored after finishing a long rest.

The healing benefit of this ability scales as you level (i.e. 2d8 At level 3, 3d8 at level 6 and so on)

While preforming this action any damage or negative effect to you interrupts the effect, expends 1 use of the ability and no healing is done.

Having crossed the void between life and death has left its mark on you.

Whenever you deal damage, by physical or magic means, You can expend one use of this ability to deal necrotic damage to the target and healing you for the same amount. The extra damage is 1d4 at first level and improves by 1d4 at level 3, 6, 9 and so on.

You may use this ability a number of times per short rest equal to your Constitution modifier. 

Undeath has granted you these traits:
• You count as undead for the purposes of magic that would detect undead creatures, such as detect evil and good or a paladin's Divine Sense feature.
• You do not need to eat, drink, or breathe.
• You gain Darkvision, but are also colour-blind
• You can't naturally sleep. To achieve the benefits of a long rest, you must spend four hours in a motionless and inactive state.
• You have Necrotic Resistance and do not suffer the negative effects of Necrotic damage.

Your will is iron. When you fail a saving throw against being frightened, charmed or put to sleep, you can choose to succeed on the saving throw instead. Once you use this trait, you cannot again until you finish a long rest.