User is able to survive and adapt to underground, stuffy, low-light terrene conditions like caves/tunnels with senses, endurance and breathing adapted for such (perhaps also adapted for intense heat, if adapted for areas closer to the earth's core).
User is able to survive and adapt to underground, stuffy, low-light terrene conditions like caves/tunnels with senses, endurance and breathing adapted for such (perhaps also adapted for intense heat, if adapted for areas closer to the earth's core).