Overview
The burning frost crystal is a first-generation god core that carries paired fire-and-ice power. Its god-core ancestry runs through Kharvos and Thamrielle: Thamrielle's essence largely formed Kharvos, and Kharvos and Thamrielle were among the beings whose essence and will forged the core that later becomes Pyrathalor.
The crystal is kept among the dormant cores beneath Maraveth until Isandriel takes it in search of a protector, hoping to find someone capable of wielding it.
Appearance
The crystal is small enough to carry in a robe or pocket. Its surface shifts between fire and ice, burns and freezes when Isandriel touches it, and develops swirling frost-and-flame colors. After Isandriel and Thamrielle force it awake in Morozkaya, its colors dim into pale streaks of essence.
Properties
The burning frost crystal can respond to potential wielders. Compatibility matters. Dalren produces only a brief shiver from the crystal before it goes inert. Isandriel and Thamrielle force the core awake by channeling into it together with essence cores and the surrounding land's essence.
That forced activation creates Thalor as a separate divine being. The result is unstable and incomplete at first: Thalor emerges from the volcanic glacier as an obsidian being, and the crystal remains in Isandriel's possession afterward. Viviana's later activation with Thalor triggers the fire-and-frost eruption that transforms him into Pyrathalor.
History
Isandriel first tries the crystal with Dalren in Radiance Prime. Dalren channels fire magic and essence into it. The crystal shivers briefly before going inert.
Isandriel then takes the crystal to Morozkaya with Thamrielle. They channel into it together with essence cores, drawing power from the glacier, snow, and land around them. The forced activation melts ice, triggers volcanic upheaval, and raises the obsidian being who names himself Thalor.
Years after the Morozkaya activation, Isandriel gives the crystal to Viviana near that same obsidian being. Viviana has the being channel essence into the crystal with her. The result devastates Radiance Prime with fire and frost and transforms Thalor into Pyrathalor.
Balthazar eventually carries the burning frost crystal. Pyrathalor chose him as the crystal's first wielder so they can protect Morozkaya.