Arven takes up space before he speaks: tall, broad through the shoulders, and so still that people unconsciously leave a clear ring around him. His skin has the dry, fine-grained look of fired clay, with faintly luminous lines beneath it that brighten like banked coals when he casts. He smells strongly of wet stone after lightning, hot iron, and the bitter citrus oil he rubs into his gloves; he knows about the citrus, but not how far the other scents carry. His movements are economical and grounded, until danger comes, when his spine uncoils with reptilian speed. In his hybrid form, overlapping charcoal scales rise across his throat and forearms, his jaw lengthens into a blunt draconic muzzle, and elemental light leaks between his teeth like a furnace seen through a cracked door.

Arven is patient with practical questions and merciless with what he considers sentimental delay. He can be unexpectedly generous to workers and children, then dismiss the same people's right to choose their own risks. In private, grief makes him meticulous rather than openly sorrowful; when a plan fails, he becomes blunt and physically restless. He wants to be remembered as a protector, but distrusts anyone who would protect people by a different method.

Arven was raised above a kilnworks in the soot-heavy town of Sootbridge, where his mother, Oda, shaped roof tiles and his father taught sums to apprentices. As a child, he learned to tell the temperature of a furnace by the smell of its smoke. At twenty-six, while studying a buried draconic observatory, he triggered a dormant elemental engine. The resulting eruption killed his mentor and buried an entire neighborhood beneath molten glass. Arven survived by drawing the engine's power into himself. The experience changed his understanding of magic: he began to see natural disasters as failures of design, not forces to be endured. He now intends to bind the region's elemental vents into a single controllable system, convinced that his rule will prevent another catastrophe. His sister Oda still runs the family kiln and publicly denounces him, though she secretly sends him old family recipes and asks him to leave the town's waterworks untouched. His former apprentice, Beren, has stolen a set of engine schematics and is trying to warn the towns around the vents. Arven has not ordered Beren's capture, but his agents are closing in. Meanwhile, the engine under Sootbridge is waking faster than his calculations predicted.