Fusion was a villain that appeared during Paul Jenkin's run of
Peter Parker: Spider-Man all the way back in 2001. IMO, Jenkins' run during that time (#20-50) is one of Spidey's best. He really got the character. Jenkins had a later run on
Spectacular Spider-Man, but that wasn't as good, unfortunately. A lot of his recent work has received a fair amount of scorn (he created the infamous character of Sally Floyd and wrote the debacle where she roasts him for not using MySpace), but looking back at his older stories, they still hold up.
Fusion had a lot of potential for a character, as this arc hopefully shows, but he seems to have taken a powder after Jenkins left. His last appearance was in 2002, and it seems unlikely that he'll return. Which is a shame, as he was a far more interesting character than Menace, Kraven's daughter or any of the other BND rejects....
( Scans under the cut...(image-heavy) )