
A powerful artifact designed to destroy a cult to demons attempts to reason with or forcibly control its wielder to achieve its foul ends. The ambitious could forge a pact with it for power… but at what cost?
Background
The Brightblade is a powerful longsword forged by angels thousands of years ago with one purpose: destroy all demons. The weapon was granted a measure of sentience to achieve this goal, but has become obsessed over the centuries. It attempts to pursue its goal… by any means necessary. It fell into the hands of demon cultists who were unable to destroy it and instead locked away. The players likely find it deep in a cult’s hideout, locked in a metal strongbox and sealed with abyssal magic. The blade is a gorgeous metal longsword, engraved with runes in Celestial, and is clearly of divine origin.
Situation
The Brightblade wants to be wielded in combat against demons and their followers. It can attempt to do so through negotiation or by attempting to seize the mind of those who wield it. The Brightblade immediately opens up conversation with whoever picks it up, speaking in a righteous and self-important manner (see the Brightblade social stat block for more information).
The Brightblade can be introduced in a variety of ways. If you are unsure of how, pick an option from the following list or use it as inspiration:
- Dead Man Walking: A crazed lunatic has been running around with the Brightblade, screaming how they will purge the wicked from this world.
- Maximum Security: Demons have buried the blade as deep as possible—the bottom of a dwarven mine, for example, or in a massive elven vault. Where one might expect a massive pile of gold, there is only a single sword protected by demonic magic.
- Angelic Boon: Angelic crusaders grant the sword to those they believe are perfect vessels with which to slay the demonic interlopers.
- Failed Destruction: The sword is found floating on a pool of lava. Perhaps someone failed to destroy it?
- Massive Skull: The sword is stuck in the skull of what was once a massive, massive balor. Only one who the sword believes is worthy can draw it.
Goals
Goals
There are two primary groups interested in the Brightblade at the moment:
- The Brightblade itself wants to be wielded. It requires a wielder to do anything important, and as such is willing to take drastic measures (such as mind control or offering incredible celestial power).
- The demons of your world (and their followers) want the thing locked away, or even better, destroyed. The blade is a massive threat and has proven itself immune to the usual smashing or melting.
Using These Encounters
What do your player characters want? What are their best and worst qualities? What goals are they pursuing? Read through a few of the examples below, then choose the encounter that best suits your situation.
- If your characters are particularly pious or serve a zealous god, run Encounter A. If they are willing to do anything for power or serve an evil patron, run Encounter C.
- If you have players who enjoy moral dilemmas, run encounter A. If your players enjoy the thrill of battle and problem-solving, run Encounter B.
- If you have player characters who need more power to achieve a goal, run Encounter A.
- If you have characters who have morally gray motives, run Encounter B or Encounter C.
- If your characters harbor grudges against one another, run Encounter B.
- If you have characters looking to destroy a faction, you have two options: run Encounter A for those trying to attack the demons, or run Encounter C for those hoping to harm the angels.
The Brightblade
Weapon (longsword), Very Rare (requires attunement)
This powerful blade was forged to slaughter demons, and granted a measure of sentience to achieve this goal. It gains a +2 bonus to all attack and damage rolls, as well as the following features:
Radiant Strike: The Brightblade deals an additional d6 radiant damage on damage rolls.
Purge the Wicked: As an action, a creature wielding the Brightblade may learn the location of all demons within 500 feet. Once this feature has been used, it cannot be used again until the next dawn.
Live By the Blade: The Brightblade can cast Dominate Person (DC 17) once per day, regaining use of the spell at dawn. It does this of its own accord, and wielders do not have access to this ability. Any creature attuned to the Brightblade has disadvantage on the saving throw.
Improved Features: If the Brightblade sees fit, it can grant these additional properties to the wielder.
Searing Strike: The additional radiant damage dealt by the Brightblade increases to 2d6.
Blinding Radiance: When a creature is dealt radiant damage by the Brightblade, it loses any blindsight and truesight it has for 1 minute. It must also succeed on a DC 16 Constitution saving throw or be blinded for 1 minute, repeating the saving throw at the end of each of its turns and ending the effect on a success. Once a creature succeeds on the saving throw, it is immune to the blinding effect of this property until it finishes a long rest.
Cloaked in Light: As a bonus action, the wielder gains temporary hit points equal to three times their level. Once this property has been used, it cannot be used again until the next dawn.


Encounter A
In this encounter, the Brightblade attempts to negotiate with its wielder to bring it into battle against various demons.
Setting up this Encounter
This encounter involves the Brightblade trying to talk a character into giving up a piece of their independence for power, as well as go into battle against demons. If your players are pious or serve a zealous god, or if they enjoy moral dilemmas, make the Brightblade particularly bloodthirsty, speaking of the righteous sanctity to be found in slaughtering the evil servants of demons, as well as their spouses and children.
If you have players that need more power to achieve a goal, emphasize the power the Brightblade can offer. Make it talk up the benefits it can provide, offering incredible benefits, and perhaps even consider using a more powerful version of the weapon by increasing its bonuses to attack and hit or upgrading one of its abilities.
If you have players looking to destroy demons, whether for their god or due to some grudge, make the Brightblade almost evil in its obsession with destroying demons, and perhaps even a little untrustworthy. Try to make it nearly sound like a demon itself, offering a fell deal for power, emphasizing the moral implications of an endless crusade.
In this encounter, Brightblade gains the following ability:
Pact Control: If a character enters a pact with the Brightblade, it can affect the wielder’s actions. At any time, if the wielder attempts to do or say something the Brightblade does not approve of, the wielder must succeed on a DC 17 Wisdom saving throw or be incapable of taking that course of action. The wielder may attempt another tactic without wasting an action.
Action!
When a character picks up the Brightblade, it immediately initiates telepathic communication, introducing itself as a destroyer of demons and powerful relic of the angels. The blade offers to grant the wielder great power if they agree to destroy any demon or follower of a demon the blade believes it sees.
Part of this bargain (which the character should be made aware of) allows the Brightblade to control certain aspects of their life— whether they are physically capable of speaking to those the sword deems unworthy, or even negotiating surrender or conversion of demon worshippers.
If the character agrees, they can attune to the sword as an action, gaining the full strength of its benefits— and its drawbacks.
If the character refuses, the sword grows angry and pleads, then threatens the character, demanding they wield it before attempting to cast Dominate Person on the new wielder (DC 17) and storming off if successful. The blade quickly becomes a hindrance.
Resolving this Encounter
If your players are pious or serve a zealous god, working with the Brightblade likely pleases them. Attuning to it grants them great power, a reward in and of itself, but refusing it could cause complications with their god. Devoted priests may start refusing aid, or a faction of zealots may try to steal the sword.
If your players need more power to achieve a goal, attuning to the Brightblade certainly provides this. If your players enjoy dilemmas or complex situations, the backlash of this attunement could be more severe, but if they prefer a more laidback game and simply want a good reward, it is probably for the best to keep the issues to a minimum.
If your players want to destroy demons, the Brightblade can give them very specific information about demon lore and important locations for demons. It may be aware of a true name, an important (but possible to defeat) demon, or influential political figures who are secretly cultists.
Encounter B
In this encounter, the Brightblade doesn’t establish communication until the players have returned to civilization. It believes all surrounding creatures are demon worshippers and asserts control over the wielder to attack them.
Setting up this Encounter
This encounter involves intense combat and a difficult situation. If your players enjoy combat and problem-solving, play up the intensity of the battle. Consider giving the Brightblade two or even three uses of dominate person, allowing it to prolong the battle or draw in new players as its potential wielder.
If your players are morally gray, consider having Brightblade make the offer from Encounter A even as it rampages through civilians. Are the characters willing to take the deal from a clearly homicidal maniac?
If the players harbor grudges against each other, have the Brightblade capable of reading the character’s basic memories when it controls them, allowing it to gloat at and otherwise provoke the players.
Action!
The next time the party is in a busy or crowded area, the Brightblade immediately uses its Live by the Blade ability on the player that wields it as soon as it can sense other creatures moving about. The sword then uses its new flesh puppet to walk towards the nearest unfortunate peasant and strike them down where they stand. The Brightblade’s puppeteering is made more potent by its Improved Possession ability.
Assuming combat begins, the Brightblade retaliates against any creature that attacks it, using the full brunt of all of its abilities. The battle only ends when the Brightblade is physically incapable of possessing another person.
In this encounter, Brightblade gains the following ability:
Improved Possession: The Dominate Person effect of Live by the Blade is improved, but only against those who wield the sword. Any instance of damage lower than the wielder’s Constitution score does not prompt a save to end the effect.

Resolving this Encounter
For players who enjoy combat and problem-solving, consider having local forces reward them for subduing their ally, and perhaps even paying for the group to hand over the sword. Alternatively, the encounter could lead to more battle as the town guard arrives or the possessed character flees with the sword.
If your players are morally gray, consider having the sword offer its power as in Encounter A. Alternatively, one of the factions could hear of the incident and offer a deal for the sword.
If the characters harbor grudges towards each other, consider having the town guard arrive to break up the fight if necessary. Introduce the sword as a more significant threat, perhaps by having it possess a peasant and escape, swearing revenge on the “demon coddlers” for refusing the call and giving a decent reason to avoid killing each other for now.

Encounter C
In this encounter, a group of demon worshippers and their glabrezu leader ask the party to destroy the Brightblade.

Setting up this Encounter
This encounter involves a powerful demon (a glabrezu) and his followers approaching the party, so if they would do anything for power or serve an evil patron, hammer that connection home by associating the demons with groups they’ve interacted with in the past. Perhaps the glabrezu is a servant of the warlock’s patron, or the cult was allied with the party in the past as part of their ambitious plans.
If your characters are morally gray, play up the horrific goals of the demons. Consider having the glabrezu test the sword on one of his followers to see if it’s legitimate, or describing their hatred of the angels. How far will the characters go for the power the demons can offer?
If the party is seeking to destroy angels, have the demons offer to assist the group in exchange for the destruction of the sword. A glabrezu is a powerful ally, perhaps providing insight into angelic secrets or even assisting them in a fight against a foe they wouldn’t normally be able to handle.
Action!
Some time after finding the sword (how long depends on how they found it, but likely a week or two later), the party is approached by a glabrezu named Gorecharge and 12 cultist followers he has. The group seeks out the party in a private place, such as the wilds or if the party ever enters another demon cult hideout.
Gorecharge offers the party a considerable reward for finding a way to destroy the Brightblade— the reward is equal to 100 gold pieces times the party’s average level times the total number of characters, assuming they’re successful. He can also offer the gift of the demon, a powerful magical boon to one character out of the group.
Destroying the Brightblade is a difficult task— a character that succeeds on a DC 15 Religion or Arcana check can recall celestial artifacts are often immune to physical harm, but powerful natural effects (such as the lightning of a storm giant or the breath of a dragon) is capable of melting the blade. Characters who fail this check will need to do some research in the library to uncover this information.
Exposing the blade to 50 or more damage from an appropriately powerful source destroys it instantly. Otherwise, the blade is impervious to all damage.

Resolving this Encounter
Gift of the Demon
The character gains resistance to fire damage, becomes fluent in Abyssal, and once per turn, may deal an additional d6 of damage on any damage roll against Celestials.
If the party would do anything for power or serves an evil patron, certainly consider giving them the gift of the demon as part of their reward, as well as the goodwill of their master if applicable. Literal power for evil acts drives their agenda forward.
If the characters are morally gray, drive home the foul deed with some physical reminder of their crime— the Brightblade marks their body permanently, decreeing them an angel slayer. Marks could include demonic features such as horns or a divine sigil on their forehead meaning “murderer”.
If the characters are seeking to destroy angels, consider allowing them to bring their newfound allies with them against an angelic ally, or even rewarding them with an arrow of slaying that is designed to kill celestials or angels.