The Vein Fever manifests as a spectral sickness around its bearer - not visible marks, but an atmospheric distortion. Air shimmers around them like heat rising from desert sand. Their shadow moves independently, flickering with greenish light. Competitors near them report hearing whispers in their heartbeat, as if the frontier itself pulses through their veins. Those who carry the Fever gain fever dream vision - the ability to see through the Deadlands' deception and perceive true scores.

The Vein Fever represents those who have been touched by the Deadlands' curse and survived, becoming walking vessels of the frontier's contagion. They spread the Fever to new leagues unknowingly, connecting all leagues through a disease metaphor that emphasizes the series-spanning connection while maintaining the survival theme.