There have been mixed reactions regarding the appearance of Raiden from
Metal Gear Solid 2 as a non-playable character in
MGS4. Raiden has transformed into a cyborg. The details of his transformation are known, other than it being necessary due to a severe trauma. The only human parts remaining are his head and spine. His blood has been replaced with artificial white blood. The designers' perspective to the change was partially to regain male fans with his appearance being perceived as "cooler" and more manly.