Blues, or Proto Man, is Rock’s older brother who ran away from home. The original robot. Mysterious and rebellious, he is way cool. Sometimes he fights you, but he is often on your side. He is assuredly not the same person as Zero, as Zero was being built while Blues was still around, but they share many parallels. Just look at that flowing yellow scarf, and Zero’s beautiful hair!

Their attitude is very similar too. Unlike other robots, they don’t follow orders. They act by their own choice, and stand aloof while actually being very loyal to their friends. They both have dark pasts. Actually, now that I think of it, why not make them the same guy? It requires some serious canon massaging, but it fits quite well thematically.

Blues has been aligned with Dr Wily in various sources after being repaired by him, and Zero was built by Wily. Who’s to say he didn’t take some cues from Blues with the design, if nothing else?

Anyway, Blues is first encountered with no knowledge of his history, but Rock finds out that he’s his brother eventually. He will often help out Rock, but largely keeps himself separate. He has some trust issues.

Zero is a very competent Maverick Hunter, a superior to X. X looks up to him but over time the two become comrades in arms. Zero later finds out that he was built by Dr Wily, and was the cause of the original Maverick outbreak. He has a very cool personality but has formed some relationships, some of which have caused him pain (Iris).

Zero eventually deactivates himself, but is awoken a century later to find himself in a new body (third image). The new world he finds himself in is ruled by a copy of X, his old friend. This copy is nothing like X however and rules as a tyrant. Zero fights the copy X and his shadowy master, Dr Weil, with the help of the real X, now a Cyber-elf ghost. He eventually dies to protect the remaining humans.

Zero lives on in Biometal form, giving his power to a Reploid host (fourth image) so as to continue fighting Mavericks. He later combines with X’s Biometal, passing on the best powers of both to new heroes (fifth image).

Both Proto Man and Zero have counterparts in the parallel Network world. Proto.EXE wields a sword weapon, which in my mind strengthens the link between them. His role in those games is somewhat similar to Blues, although the connection to Rock is lost. Zero.EXE’s role is like Wily’s original intention for Zero, to be a virus carrier and agent of carnage.