Resurrection Diamond

Bringing the dead back is possible, and it consumes a rare diamond as its material component. The stone is destroyed doing it. There is no known way to bring back the same person twice on one gem, and no known way to make more of them.

This is why the great figures of the age keep dying and coming back while everyone around them stays dead. It is not that death is weak. It is that a handful of people were carrying diamonds.

Gyllyn's Armure is the thing that performs the work, and it is the only thing in the world that can. The spell exists nowhere else—not in Cerberus, not in the Ark, not in Askenon—because Armure is Manatar's, and what a creator god built into his own armor was never written down for anyone else. It still needs two inputs it does not own: a diamond, and mana lent to it by a living caster. Aldor gathered the frozen fragments of Frolix after the Minotaur, spent his last diamond, and gave Armure his mana; Frolix came back stronger and not quite the same. Adraya was returned with the diamond she happened to be wearing herself, minutes after Gyllyn had killed her by accident.

A party that owns one owns a single reversal, and knows it. A party that spends it has spent it.

For the GM. This is the cleanest lever the setting has over death, and it is deliberately one-sided. A party travelling with Armure can be given a way back that the world does not otherwise offer, without the GM inventing an exception each time somebody dies—and the enemy has no equivalent, because there is no second armor and no second formula. A villain who dies is finished. That asymmetry is a feature: it is the reason the same handful of names keep walking out of catastrophes while everything they fight stays buried.

Hand out a diamond and a table plays differently for months: it takes risks it would not otherwise take, argues about who is worth the stone, and remembers the night it was spent. Do not price them. Place them.