Nighthawk is initially opposed to the Superhuman Registration Act during the "Civil War" storyline. Following the death of superhero Black Goliath at the hands of the cyborg clone of Thor on the Pro-Registration Side, Nighthawk joins the Pro-Registration Side, but is defeated in a skirmish with Anti-Registration heroes Falcon and Storm. He later joins the US government's Fifty State Initiative of registered heroes, and forms a short-lived Initiative version of the Defenders with the mutant Colossus, the Blazing Skull, and She-Hulk. With She-Hulk and Warlord Krang, Nighthawk battles the group the Sons of the Serpent, which culminates in a confrontation with his old Defenders foe Yandroth. Yandroth manipulates time and forces Nighthawk to battle a twisted version of his old team the Squadron Sinister before being rescued by a future incarnation of the Defenders. Noting that one of the future members is Joaquin Pennyworth, an agent of S.H.I.E.L.D. and the son of the one-time leader of the Sons of the Serpent, Richmond asks him to commence training to become the new Nighthawk. During the "Fear Itself" storyline, Nighthawk joins Howard the Duck, She-Hulk and Frankenstein's Monster to form the Fearsome Four when Man-Thing is driven on a rampage. They later discover a plot by Psycho-Man to use Man-Thing's volatile empathy to create a weapon. Nighthawk is a superb athlete who, courtesy of an alchemical potion, possesses enhanced strength and increased agility and durability from dusk till dawn. He has also used several costume aids, such as a jet-powered artificial wing system, artificial claw tips, lasers and projectile weapons. Roy Thomas and penciller John Buscema created an alternate-universe team of heroes called the Squadron Supreme, who debut in "The Avengers" #85 (Feb. 1971). After an initial skirmish with four Avengers, the teams unite to stop a common threat. The characters (including Nighthawk) were identical in name and appearance to the Squadron Sinister, which caused confusion in Marvel's production department, as the covers of "The Avengers" #85 and #141 (Nov. 1975) "cover-blurbed" appearances by the Squadron Sinister, when in fact it was the Squadron Supreme that appeared in both issues. The heroic Nighthawk and the Squadron Supreme have another series of skirmishes with the Avengers engineered by the group the Serpent Cartel, but eventually team together and prevent the use of the artifact the Serpent Crown.