Pyre is one of the five affinities, the colours of power that leak into the Hallow through the imperfect Covenant. It is the affinity of fire, destruction and war, and Undon, the Unmaker holds it. Its art is Unmaker's Edge, which Undon, the Unmaker teaches.
On the ring of affinities, each affinity feeds the next. The dead burn, so Umbra feeds Pyre. Ash nourishes growth, so Pyre feeds Bloom.
A Sealborn whose core wakes in Pyre can master its spells and reach the complex spells of its neighbours. Lumen and Reverie lie across the ring and repel it. From them, such a mage learns only the simpler spells, and casting against the grain costs more, fails more easily and lands weaker. The exact prices belong to the ruleset.
Cultivators of Pyre are not ashamed of their affinity. Nothing the fire takes is wasted, they say, because the ring carries it on as ash into growth.