I belive hes just another program in minecraft, just like zombies, sekeltons, and creppers, the onlt diffrencee between them and him is he can adapt, build, and ulimantly exterminate you, so i would say the best thing to do is live in a town and only go out at day and only if somebody is with you or you know someone will accept your teleport request
P.S. i belive i saw him in one of my singleplayer server. he was standing on top of one of my buildings and when i typed /kill npc (becuase i thout it was a zombie) and it diddent die, i went closer and i saw that the eyes were glowing and then i died right then and my game crashed, FREAKYYYY!!!!