Hagen is a tall, lean warforged constructed from dark ironwood, blackened steel, and brass fittings. Fine arcane conduits glow faintly violet beneath the seams of his armor plating. His face is a smooth iron mask with a narrow, amber crystal visor, and his left forearm has been rebuilt into a modular weapons platform covered in interchangeable tools, lenses, and rune-etched components. His scale mail is stained with oil and soot, while a faded guild insignia is stamped into the breastplate.

Hagen is intensely curious, irreverent, and theatrically confident. He speaks of battlefields as testing environments and describes magical phenomena with the enthusiasm of a craftsman unveiling a new machine. He is capable of genuine loyalty, but his attention is easily captured by a new rune, a strange corpse, or a device that should not function. Hagen rarely lies about his intentions, though he frequently leaves out the most alarming portion.

Hagen von Geist was built in a cramped workshop beneath the observatory of Doctor Albrecht Geist, a scientist whose name never found its way into the great academies. Geist was fascinated by the boundary between physical law and arcane possibility, and he designed Hagen as both assistant and proof of concept. His final command was simple: investigate the true art of combining science with magic, then return with knowledge worthy of remembrance. The doctor died before Hagen could ask what success was supposed to look like. After his creator's death, Hagen joined a guild of artisans and engineers, presenting himself as a traveling specialist in experimental devices. He learned the practical crafts of metalworking, repair, appraisal, and trade, but honest commerce could not contain his curiosity for long. Ancient libraries, ruined laboratories, and monster-haunted dungeons became his laboratories. He now pursues forbidden rituals and lost arcane formulae, not merely to understand them, but to build weapons powerful enough to challenge beings worshiped as gods. Hagen insists that this is research, not ambition. The distinction grows less convincing with every device he completes.