I have no idea i couldn't find this information anywhere
I'm just playing scaling and enjoyed this show so i wouldn't call myself an expert because i don't even remember some of character names actually but i definitely recommend watching this anime because it's one of the most mature and depth in which there is a lot of emphasis on the characters feelings and main character development. animation is really good too fights are smooth and interestingly realized. if you like the parasite thread where most of them look really disgusting.
Turner Blackey it's just great anime
Migi enhanced Shinichi traits i.e. better reflex strength, etc when he was nearly dead (this made him sleep several hours a day) he's able to overtake cars or jump over obstacles several meters long.
Although on the other hand he is still main protagonist so it's probably plot armor ;d