Major Story Arcs
Skylancer is a supervillain in 1960s Chicago, the last of the Chicago Six, which was the main supervillain group of the era, starting around the end of World War II. They provide the most significant opposition to the superhero union, C.O.W.L. Skylancer is a prominent enough antagonist to C.O.W.L. that they use an image of him on their target-shooting range.
Skylancer is a Soviet. He uses advanced technology and weapons, some of which he gets through a backdoor deal with Alderman Lowe. (Lowe is sleeping with C.O.W.L.'s boss's secretary, who gets the plans for him.) One day Lowe meets with him about the technology, but C.O.W.L. finds out and thinks that Skylancer is trying to kidnap or kill the alderman.
The union heroes attack, trying to save Lowe. Skylancer blows up the apartment, forcing Blaze to save himself and the alderman, and flies off. Radia catches him with her telekinesis, but he blinds her with a flash grenade and escapes again. Arclight grabs him but Skylancer forces his arm to shoot Blaze instead. Skylancer ties Arclight's cap to his own jetpack, and Arclight flies off, out of control. Skylancer falls to the ground and starts killing civilians indiscriminately. The blind Radia, aided by Recon's targeting abilities, uses her TK to snaps Skylancer's neck, killing him.
The end of the Six means that C.O.W.L. has no more significant super-powered enemies. This leads the city to want to alter their contract, which Warner and the union don't want, and drives the whole storyline of the C.O.W.L. comic. At the end of the series, someone anonymously mails a gas mask that looks like Skylancer's to disaffected C.O.W.L. member Grant Marlow; presumably he takes on Skylancer's identity in the future.
Powers & Abilities
Skylancer seems to have no powers, but relies on advanced technology, at least some of which comes from C.O.W.L. This includes a winged jetpack, a grenade launcher with explosive and flash grenades, energy-projecting guns, a gas mask, and some level of added durability in his costume, enabling him to fall several stories onto a car and still be capable of combat.
In Other Media
In the movie The League (which was created before the comic and whose in-universe history is largely although not entirely the same as the comic) various supervillains are named or appear. While they don't use the name "Chicago Six," presumably some of them would have been in the Six if it had been so named, and possibly would have appeared in the comic if the comic series had lasted longer. They include Big Ivan (who helped created the "Fearsome Five," clearly a forerunner to the Chicago Six), Dmitri Popov, and Nicolai Lennin. Since all of these have Russian names, one of them may be the template for the comics version of Skylancer. (At one point in the comic, a C.O.W.L. member calls Skylancer "Ivan," but that is probably just a colloquial phrase for a Russian, and not actually his name.)