Here are the draconian relics that appear in this adventure.
This is a giant obsidian bowl, twenty feet wide and twenty feet deep, which fills itself with pure fresh water. When the water is removed from the pool, it is normal water with no magical properties. If the water is drank directly from the pool, it instantly grants the drinker the benefit of a long rest. A character can only receive this benefit once between any pair of actual long rests.
The Miracle Spring is the reason for this village's existence. This is both because it's a source of fresh water in the desert, and also because people come from everywhere in the Empire to live near it. Some of the town's inhabitants are minor sages who like to be able to stay awake longer to do their research. Others are minor magic users who like getting twice as much magic per day. Yet others are minor lords who like being able to party through the night.
Anyone with real power generally won't be found here -- they need to be elsewhere to do their important work.
(The function of the Miracle Spring in this game is to give the chararacters a chance to regain their spells and hit points. This game is on a pretty strict time schedule, so characters otherwise would not have a chance to long rest. Players sometimes assume that the Miracle Spring holds some power that can be used to de-curse, or otherwise purify, the Six Weapons. This is false.)
These red tokens are engraved with the image of Tiamat, but the red head of Tiamat is particularly prominent and is larger than the rest. The tokens feel uncomfortably hot to the touch. Several caches of these have been found in various dig sites nearby, and the cultists have collected several of them. If a character has pledged their soul to Tiamat, they can use this symbol to generate a flamethrower-like effect at will. Characters who have not pledged their soul to Tiamat get no benefit from these tokens.
These six weapons are capital-A Artifacts, created by the ancient draconian clans as part of the war that destroyed their species. Each of them grants the bearer great power, but each of them constantly fights with the bearer for control. The weapons seek indiscriminate slaughter and destruction.
The weapons lay dormant for hundreds of years in a crypt, but recently they have been awakened by the touch of fresh blood, and it will take years before they return to slumber.
Any character who touches one with their bare skin is likely to fall under that weapon's control. Touching a weapon through an insulating material is still dangerous. Even if one of the weapons is not being wielded, it may still exert its mental influence at a short distance away, trying to force someone to pick it up.
The weapons cannot be destroyed by mundane means. No amount of striking the weapons with a hammer or heating them in a furnace will damage them. One of the weapons is supernaturally good at destroying objects, and this weapon has the power to destroy the other weapons, but other than this there is no way to destroy these weapons within this adventure module.
The weapons are:
the RIGHT HAND OF DARKNESS -- this resembles an oversized obsidian greatsword, but it's more ornate. In some places it is jagged, in others smooth; in some places it has extra blades and protrusions, in others it has grooves. It can grant its bearer the ability to lift and swing it.
This weapon hates all living creatures and is especially good at killing them. When the bearer kills a creature with this weapon, the bearer absorbs that creature's life force, and will automatically use that life force to heal if injured. Any creatures killed by this weapon rise twenty seconds later as undead creatures under the weapon's control.
If a character falls under this weapon's control, they attack all nearby living creatures, giving preference to those that might be a threat. The weapon seeks to slay living creatures and convert them to undead under its control.
If a character is wielding the weapon and has resisted the weapon's mind control, the character can attempt a mental contest to give orders to the undead raised by this weapon.
the LEFT HAND OF DARKNESS -- an identical twin to the RIGHT HAND OF DARKNESS. Presumably these were dual-wielded by some very large draconian monster of some sort.
the ORB OF LIGHTNING -- faint yellow sparks dance in the depths of this blue crystal ball. The holder of this orb can launch great bolts of lightning with a thought.
If a character falls under control of the orb, the orb launches bolts of lightning at all nearby targets, seeking only to slaughter and destroy.
Holding this orb gives no special protection against electricity, including the orb's own electricity. If a bearer displeases the orb, the orb might turn its electricity against the bearer. The orb only does this if there's another potential bearer nearby which it would prefer to be held by.
the BLADE OF SHADOW -- this obsidian dagger is shrouded in darkness. It grants the bearer the power to create darkness surrounding them, the power to see in darkness, and the power to move quickly and stealthily while shrouded in darkness. The blade inflicts bleeding wounds, and a character wounded by this weapon may eventually die of blood loss if the wound is not attended to.
If a character falls under control of the blade, the blade creates a large field of darkness and attempts to stealthily kill all who enter it.
the KINETIC ORB -- this obsidian ball has three finger holes, not unlike a bowling ball. It grants the bearer the power to throw it with great accuracy and power. If it strikes a target, it propels the target backward with tremendous force. If it strikes anything, it teleports itself back into the bearer's grasp, ready for another throw.
If a character falls under control of the orb, the orb throws itself at whichever targets (living or non) are nearest until everything is destroyed.
STONECRUSHER -- this obsidian greatclub is marbled with streaks of adamantine, though it's hard to imagine what forging process could have created a weapon that contains "streaks" of that metal. It grants the bearer the power to lift and swing it easily.
This weapon hates inanimate objects and is especially good at destroying them. If a character falls under control of the bearer, they seek to destroy objects and buildings nearby, which may lead to them getting crushed under rubble from a falling building.
This weapon can destroy the other five weapons if it strikes them directly. The weapons release destructive energies when destroyed. The hands of darkness release negative energy which drains the life of those nearby; the blade of shadow releases darkness which blinds those nearby; the kinetic orb explodes with great force which flings everyone away. The orb of lightning releases lightning.
It will frequently occur during the adventure that a character will interact with an artifact. Here's how to run that.
If a character touches an artifact with their bare hands, the character faces a very difficult mental contest. (In D&D 5e, I usually ask for a DC20 Charisma save.)
Failing this contest means the artifact has taken control of the character's arms and legs. I usually describe this as follows: "an icy sensation flows into your hand, up your arm, and throughout your body. Your body has stopped obeying your commands." The character can still speak normally, can cast spells if they use only verbal components, and may be able to take other actions at your discretion. The character does not receive a new saving throw every round, but might receive a new save if something specific happens to allow that. For example, in one game a player tried throwing holy water at a character that was controlled by an artifact, and I ruled that this would allow the character to make a new save with advantage.
Succeeding at the mental contest means that the character can use the artifact normally for a short time. Soon the artifact will attempt to reassert control, which will require another save. This might happen at the end of combat, or (if combat takes a long time and the artifact feels impatient) it might happen whenever the artifact fells a foe.
If a character is standing near an unattended artifact, the artifact may whisper words to that character in Draconic, asking them to pick it up. To avoid picking it up, the character must succeed at a mental contest. This is a much easier mental contest than the one from touching an artifact directly -- in D&D 5e, I usually ask for a DC 8 Charisma save. The artifact may do this once per round.
If a character holds an artifact through some insulating material, it's the same as touching the artifact with bare hands, except that the mental contest is easier -- in D&D 5e, I usually ask for a DC 14 Charisma save.
The most obvious way this might happen is if a character finds the golden gauntlets, which are intended for this purpose. Characters might also improvise an insulating material by wrapping an artifact in a blanket or bedroll, though this might give disadvantage on attack rolls.
If a character employs anti-mind-control magic such as protection from good and evil, this prevents all mind control and allows the wielder to harness the full power of the weapon for the duration of the spell. (The spell only says that it protects against "aberrations, celestials, elementals, fey, fiends, and undead", but it works against evil artifacts as well.) Note that this spell is Concentration-based, and don't forget to request a concentration check if the caster is injured while the spell is active.
If a character attempts to disarm someone holding an artifact, follow the normal disarm rules. In D&D 5e, that would be:
A creature can use a weapon attack to knock a weapon or another item from a target's grasp. The attacker makes an attack roll contested by the target's Strength (Athletics) check or Dexterity (Acrobatics) check. If the attacker wins the contest, the attack causes no damage or other ill effect, but the defender drops the item. The attacker has disadvantage on its attack roll if the target is holding the item with two or more hands.
If a bare-handed character (perhaps a monk?) successfully disarms someone, I offer them the chance to take the artifact for themselves -- ie, at the end of the disarm attempt, they are holding it. Wise players decline this offer.
If a character who understands magic attempts to understand what an artifact is, I try to give them a lot of information. Having more knowledge makes the game more fun.
If a character tries to drag an artifact behind them on a rope, they can do this without trouble. This is a good way to move an artifact without letting it mind-control you.
If a character buries an artifact in the sand, that prevents it from causing more problems for the rest of the adventure, unless the artifact was one of the Hands of Darkness, in which case some of the undead that it controls might come by and uncover it and try to find a new bearer for it. This should be pretty obvious to the group as it happens -- ie, as they go to bury the artifact, undead periodically walk up and try to take it from them.
If a character tries to destroy an artifact, I explain that destroying artifacts is quite difficult and that the traditional method is to throw them in a volcano. I don't volunteer the idea that Stonecrusher might destroy the other artifacts. Only about one-third of groups figure this out.
There are no volcanos near the Gray Desert where this scenario takes place.