Hi - looking for a tale I read many years ago! Premise of the story was there was man who hid himself within a catacomb with many traps and pitfalls to isolate himself from the world (and I believe all the noise from people IEsionics). He is eventually found and recruited to fight against the grey men. Our hero was deemed a "colonial" and gets an armor mesh embedded into his body which allows him to fight freely within all environments including space. I read the story in the late 70's