When a mortal meets a particularly cruel or undeserving end, its soul can fight its way back to the world of the living to seek revenge on those that have wronged it. The revenant reclaims its mortal body. Broken bones and torn flesh may mend, but they rarely heal fully, and remain as visible marks of their passing. Over time, their flesh will weather and toughen, turn ashen as the remains of its life ebb from the body. Superficially, revenants resemble zombies, but their eyes burn with necrotic light and flare in the presence of their adversaries. If the revenant's body is destroyed or is otherwise unavailable, the spirit can enter another humanoid corpse to resume its mission.
The revenant has but a single year to exact its revenge. When its target dies, or if the revenant fails to complete its revenge before this time, it crumbles to dust and its soul drifts off to the afterlife. If the target is too powerful for the revenant, it may take some of this time to seek allies to help it achieve its goal. At the DM's discretion, an awakened revenant may turn into a ghost or spectre if it fails to complete its revenge within a year.
Ability Score Increase
Your Constitution increases by 2. Choose either Strength or Dexterity score to increase by 1.
Unrelenting Nature
Your will was strong enough to bring you back from the dead. You are so singularly focused on your vengeance that it is nearly impossible to sway your mind. You have resistance to psychic damage. You have advantage on saving throws against being charmed, frightened, paralyzed or stunned.
Rejuvenation
Killing a revenant is no easy task. Your vengeful soul is driven to fulfil your quest. If you are reduced to 0 hit points and are not killed outright, once you make three successful death saving throws you immediately regain consciousness with 1 hit point. If you are killed outright or fail your death saving throws, your soul lingers. After 24 hours, you inhabit and animate another humanoid corpse on the same plane of existence and regain all its hit points.
When this happens, work with your DM or roll on the d100 reincarnate spell table to randomly determine what race of corpse you inhabit and change your 'past life' to that of the new mortal body. While your soul is bodiless, a wish spell can be used to force your soul to go to the afterlife and not return.
Vengeful Tracker
At 1st level, you've been brought back for vengeance on a creature or group of adversaries responsible for your death. This hunger can only be fulfilled by the death of the target or targets. You know the distance to and direction of any creature against which you seek revenge, even if you and the creature are on different planes of existence. If a creature being tracked by you dies, you know. In cases where you seek revenge against more than one adversary, you pursue them one at a time.
Sworn Revenge
Starting at 3rd level, your vengeful nature allows you to swear revenge on a creature that harms you or your allies. As a reaction, choose one creature you can see within 30 feet of you that has damaged you or an ally on its turn. You vow revenge against this creature, and it becomes your primary target of vengeance. You cannot voluntarily end or move this vow. The vow only ends when the target dies, even if you die, or you are incapacitated. Until the vow ends, you gain a bonus to damage rolls against this target. This damage equals your proficiency bonus. Any attack roll you make against the cursed target is a critical hit on a roll of 19 or 20 on the d20. You have disadvantage while attacking any other creature other than the target of your revenge.
Once a vow has ended, you can't use this feature again until you finish a short or a long rest.
Vengeful Glare
At 5th level, as an action, you stare down the target upon which you have sworn vengeance. The target must be within 30 ft and can see you. The target must make a Wisdom saving throw equal to 8 + your proficiency bonus + your Charisma score modifier. On a failure, the target is paralyzed until it takes damage, or until the end of your next turn. When the paralysis ends, the target is frightened of you for 1 minute. The frightened target can repeat the saving throw at the end of each of its turns, with disadvantage if it can see you, ending the frightened condition on itself on a success.
You can't use this feature again until you complete a short or a long rest.
Turn Immunity
By 10th level, you are so focused on your vengeance, that you are unaffected by divine powers that try to turn or destroy undead.