Not just any opal, this precious stone pulses and flashes with the rhythms of a soul that resides within. It is, if anything, an animate object. A living thing. In its own way.
The Glyph-Stone is very much aware of its surroundings and awake, even intelligent. Often more so than those who would covet or carry the thing.
Psyche: 8, INT: 12, Willpower: 22, Morale: 10
AL N, AC 3, HD 4 (Withstands 36 points of damage before exploding in a 4d8 fireball). Communication: ESP (30' radius) and Telepathy (touch). Languages: Aklo, Ashadanix (Hag-Speech), Vorut, 1d4 random additional languages. Detection Powers: Clairvoyance, Detect Magic, Read Languages, See Invisible. Spell-Like Powers: Banishing Glyph: Disperse Saiitii Influence, Oneiric Bubble, Protection from Aethyrial Intrusion, Safeguard Against Outermost Forces, Thought Wall, and Zone of Normality. Other Powers: Carrying the Gem will slow one's aging process by a 12-to-1 ratio, in other words every twelve years they only grow older by one year. Unless they lose the Gem, in which case they must make a Save for every deferred year of aging, each failure aging them one full year instantly.
The Gem will gladly bargain with anyone who carries it longer than an hour.
A Dubious Offer
For one year of the bearer's life, the Gem will teach them any of its Detection Powers as a spell, or it will teach them one of its Spell-like Powers for two years of their life. If the bearer knows Nadume's Mark, the Gem will settle for 1d4 months in exchange for any one of the spells.
What the Gem does not mention is that the time exchanged is not simply drained-away, it is the amount of time that the Gem is allowed to take possession of the body of the person making the bargain.
A Better Deal
The First Glyph can be used pretty much as one would use a Holy Word spell. It can be unlocked by those willing to make an investment of 1d4 hit points for an additional 5% chance to 'unlock' the First Glyph. Success in this effort imprints the First Glyph onto the psyche of the investor, making it a spell castable as any other in their repertoire, but outside of the usual spell-slots. It can be cast once per day, even when all the spell-slots are used-up. However, the glyph consumes one language slot. If the character does not have an open language slot, they will lose one of the languages they already have learned in order to accommodate the first glyph. Those who unlock the First Glyph accrue a cumulative 1% chance per month to access another spell from the Gem for a similar investment of hit points as before. In this manner one can avoid the Gem taking possession of their body.
A Final Offer
The Glyph-Stone can, if the one holding it so desires, transfer one of their non-physical Attributes (INT or WIS) into itself for safe-keeping. Doing this grants the bearer a permanent +4 bonus on all Saves against Mental, Emotional or Oneiric attacks or effects. It also renders them effectively immortal. They no longer age and gain a form of regeneration; they regain 1d8 hit points of damage per level of spell they sacrifice to the Gem. Spells sacrificed in this manner are permanently lost, so the Gem will suggest that they use other people's grimoires, not their personal spell-books. Scrolls deliver double the usual amount. The Gem can also teach them how to drain magical items in order to convert those energies into replenished hit points. If asked correctly, the Gem can also reveal several methods for vampirically draining life energies from living victims. But in each instance, the gem will seek to bargain for more and greater concessions from its host.
Nadume is the only being to whom these Glyph-Stones owe any sort of loyalty. They serve Her as though She were a Queen in Her wasted realm. They come when She calls to them. They obey Her commands. They do not serve Her enemies.