Air 3 is a transmission exclusive to the Neurax Worm DLC and the Necroa Virus DLC.
Neurax Worm
It gives the Neurax Worm further survival in arid conditions.
Necroa Virus
It appears only after evolving Air 2, Blood 2, and Cytopathic Reanimation.
Symptom Combos
It is required, along with Cranial Elephantitis symptom, to produce the Cranial Dispersion combo and, thus, the Use your head achievement.
