Revenants are undead creatures bent on pursuing revenge against individuals who wronged them in their previous lives. As undead creatures, they have no survival instinct per se; instead, they’re driven by compulsions, in this case the compulsion to avenge themselves.
Now, you might argue, hey, you can’t get revenge if your enemy (or someone else) destroys you. And revenants have high Wisdom, high enough to understand the truth of this—and above-average Intelligence, high enough to understand the fact of it. So you might think a seriously wounded revenant would break off fighting and retreat—that is, unless it was getting too close to its one-year deadline.
But you can’t destroy a revenant. Its Regeneration feature restores 10 hp every round unless it’s taken fire or radiant damage; only if the damage that finally reduces its body to 0 hp is fire or radiant damage will the body it inhabits be destroyed. And even when the body is destroyed, the soul returns 24 hours later in a different body.
The only way to keep this from happening is to banish the revenant’s soul to its appropriate afterlife while it’s disembodied, using a wish spell. Only the most powerful wizards and sorcerers—veritable masters of the world—will have access to that. What kind of favor do you think you’d have to do for one of them to get him or her to cast a wish spell on your behalf? (The Monster Manual doesn’t mention this possibility, but I think you could probably also stop a revenant by bringing it back to life with a true resurrection spell. But this is also a 9th-level spell; instead of wheedling a favor out of Saruman, you’ve got to get it from the pope.)
Revenants have exceptional Strength and Constitution along with above-average Dexterity, giving them a brute combat profile. They resist necrotic and psychic damage. They have darkvision, so bet on their coming for their adversaries at night. They can’t be charmed, exhausted, frightened, paralyzed, poisoned or stunned, and they have proficiency on Strength, Constitution, Wisdom and Charisma saving throws. The word “juggernaut” comes to mind. But note that they don’t have resistance to physical damage from normal weapons, so even though they have a lot of hit points, most player characters will have little problem doing damage to them. The problem is simply that no amount of damage is enough to stop them entirely.
But on to tactics. Driven by compulsion, the revenant is interested in only one target: the one who wronged it. No matter what company its target is in, it will always direct its attacks solely at that one individual. Using its Vengeful Tracker feature, it will zero in on its foe until it can see him or her. Even if its foe is hiding, it knows where he or she is, but that’s not quite enough—to use its Vengeful Glare, the revenant has to be able to see its target, and also be within 30 feet. As soon as these two conditions are met, the revenant uses this action to try to paralyze its enemy.
Next, the revenant uses its Multiattack, first to grapple its foe, then to pummel it. It makes these attacks with advantage as long as its foe is paralyzed. As long as it holds its foe grappled, it will continue to pummel, so on its first round, its Multiattack may be grapple-pummel, but on the second, it may be pummel-pummel.
Note that the target remains paralyzed only until it takes damage. Grappling does no damage, so the revenant has advantage on both the grapple attack and the pummel attack that immediately follows it. Any subsequent pummel attack rolls are made normally. However, the target remains frightened once his or her paralysis wears off.
Here’s a funny twist: To have disadvantage on attack rolls owing to being frightened, the revenant’s foe has to be able to see it. But in total darkness, the foe won’t be able to see the revenant (unless he or she has darkvision). In that case, however, the foe will have disadvantage on attack rolls owing to being blinded! Either way, the foe loses.
What if Vengeful Glare doesn’t work? The revenant will try a second time—but not a third time. Similarly, if it fails to grapple, it will try a second time but not a third time. Revenants are smart enough to adapt if a certain tactic isn’t working. If these tactics do work and simply wear off, however, the revenant will use them again after a round of normal attacks.
Clever players may use magic to make the revenant’s target invisible. This won’t stop the revenant from pursuing and attacking its foe—thanks to Vengeful Tracker, it always knows its quarry’s exact distance and direction. But it will stop the revenant from using its Vengeful Glare, and it will also give the revenant disadvantage on its attack rolls.
A revenant will fearlessly pursue a PC in a party of level 3 or 4 characters. Above that level, however, it’s going to enlist allies to keep its enemy’s companions occupied while it concludes its own business. Refer to the Unearthed Arcana “Encounter Building” article to determine how many allies it will need to enlist and how challenging those allies will need to be. The revenant itself won’t hesitate to take on its own quarry one-on-one unless he or she is level 17 or higher—one of the aforementioned masters of the world—but keeping the rest of the party tied up may require considerable manpower (and/or monsterpower). If the revenant’s body is destroyed, its allies will typically scatter, using their usual manners of flight.
Suppose the revenant’s target isn’t a PC—suppose, for instance, that he or she is an NPC whom the PCs are charged with protecting? Here’s the kicker: In that scenario, the revenant will never attack any of the PCs! It will singlemindedly pursue its foe and only its foe, relying on allies to run interference and prevent the PCs from coming between it and its quarry.
What kind of allies will a revenant enlist? They’ll have to be persuadable creatures—beings of more than animal intelligence. They’ll have to be accepting of the revenant’s mission and of the idea of partnering up with the undead. They’ll also have to share a plane of existence with the revenant, which can perceive its quarry on another plane of existence but can’t go there by itself (unless it was a spellcaster in its previous life and knew the appropriate spell), so devils and demons are unlikely, though not impossible. Religious or political fanatics, on the other hand, make fine candidates, as well as others of a race, nation or faction that the revenant once belonged to who might also see its quarry as an enemy. Other intelligent undead creatures, such as ghasts, specters and wights, are potential allies as well (and a ghast may come with a pack of subservient ghouls in tow).