In Knight of Shadows, Zelazny identifies the Jewel of Judgment as the “Left Eye of the Serpent.” In some campaigns I’ve made that literal, where it is something stolen from the Serpent by the Unicorn. But in other campaigns I’ve made it metaphorical, where it’s just one of two powerful jewels known as the Eyes of the Serpent. More recently, I’ve expanded that number slightly: why should there be only two artifacts on par with the Jewel of Judgment? What if there were more?
In recent games I’ve run, I’ve numbered them at eight as a correlation to the eight-rayed star of chaos and expanded beyond just eyes.
- The Eyes of the Serpent: the Jewel of Judgement and the Jewel of Destiny
- The Fangs of the Serpent: the Blade of Honor and the Blade of Cunning
- The Spines of the Serpent: the Staff of Wisdom and the Spear of Might
- The Hearts of the Serpent: the Cauldron of Mystery and the Chalice of Purity
Obviously these crib heavily from tarot symbolism and mythology. The Blade of Honor is a nod to Excalibur, the Cauldron of Mystery is a nod to Celtic Cauldron of Rebirth.
Usually this ties into my mythology in which the Courts of Chaos were founded by a woman named Lilith, who created the Logrus with the eight artifacts and the assistance of the serpent.
Properties of the Artifacts
The artifacts are each very powerful but they come with some serious risks as well.
Size: Each of the artifacts are capable of being carried in one hand. Only the Jewels are concealable on your person. The others are less easily hidden.
Drain Energy: The artifacts drain the life force of the person wielding it.
Low Profile: The artifacts are immune to magical detection. If you are attuned to the artifact, you can sense its presence nearby and you can even bring it to you with the Logrus. But for others it might as well be mundane. The only exception to this is when the artifact is being actively used, in which case you can tell it is being used.
Warp Shadow: The only safe place to store the artifacts is some place Real. It’s also the most obvious. But when left in Shadow the stuff of Shadow slowly warps around it. The results are always unpredictable and almost never good.
Psyche: It goes without saying that many of the more aggressive abilities of the artifacts require a superior psyche to utilize.
Basic Artifact Attunement 
Adjust Stuff of Shadow: You can create simple effects with the artifact: Change the weather, adjust time relative to yourself or others, etc. The more overt the change, the longer it takes to accomplish.
Arcane Sight: You can analyze magical energies with the artifact, just like with the Logrus.
Rack Spells: You can rack spells on the artifact, just like with the Logrus.
Reflexive Shadow Travel: When in danger, the artifact will reflexively transport you to a point of safety.
Advanced Artifact Attunement 
Volitional Shadow Travel: You can travel instantaneously from Shadow to Shadow, but it is exhausting.
Draw Upon the Artifact: You can draw energy from the artifact. This can be used to power magical effects, provide a defense against magical attacks and counter the life draining effects of the artifact. The last can only prolong the inevitable, however.
Unique Ability: Each of the artifacts possesses a unique power that can be used by advanced initiates.
- Jewel of Judgement: You are capable of astral projection. You can leave your body behind, travel through Shadows and possess the bodies of others. You are effectively intangible and unable to physically interact with the world. Powers are more draining and somewhat limited while outside of your body.
- Jewel of Destiny: With concentration, you can perceive the lines of fate. You can see the bonds that exist between people and their potential. It gives you something of an edge in social maneuvering.
- Blade of Honor: With concentration, this weapon can render you immune to all physical harm and many magical effects.
- Blade of Cunning: With concentration, this sword can cut through damn near anything. It further allows doors to be cut between Shadows.
- Staff of Wisdom: This grants psychic communication, the ability to probe weaker minds and you can consult with the memories of some of the previous users of the staff.
- Spear of Might: The wielder of this spear can draw upon the spear for physical might and military acumen.
- Cauldron of Mystery: The cauldron allows one to perceive and control a person’s dreams. Also, an advanced initiate pouring water from the cauldron while focusing on it allows one to temporarily animate the dead.
- Chalice of Purity: By having someone drink from the chalice while you focus on it, you can heal him or her. This ability also works on you.