Personality
Friendly and cheerful, but chaotic. Slingshot often acts impulsively and will dart off to try out some new idea without much consideration. Or, at least, with an excessively high confidence that he can solve any of the plan's defects on the spot
Background
Gio Visconti is from an Italian family of old wealth and lineage with roots tracing back to the island of Sardinia before it became part of Italy. He had a life of fairly easy privilege from an early age, but was raised with a sense of social responsibility. He was expected (after an allowable period of playboy antics) to join the family business of mildly corrupt Italian politics. Everything was going according to plan until a Carnivale celebration in Venice. In a festival mask ringed in sapphires, Gio strolled through the party crowd indulging all his carnal carnival whims. At the height of the party, a terrorist attack detonated a sophisticated bomb above one of the canals. The energy wave passed through stone and metal without harm, but vaporized organic materials in brilliant blue flashes. Gio himself was standing right beside the canal when the bomb exploded; the flares of people being disintegrated around him was left burned into his eyes, but inexplicably he found himself otherwise unharmed.
After recovering from the shock of the incident and his mysterious not-being-dead, Gio tried to return to his life as it was. There were surges of outrage across the country, attacks on suspiciously ethnic individuals, and the expected sort of hysteria following such an event. Gio was still in the midst of trying to figure out his own experience when he found himself in an ugly situation in Rome: a troupe of neo-fascists had cornered an intended victim on a platform of a Rome Metro station. Gio intervened, but the thugs were only more furious. Instead of being content with shouting and screaming their racist nonsense, their leader ran forward and shoved both Gio and the other boy off the edge of the platform just as a train came rolling into the station. A bright blue glow flooded the station; the intended victims had landed softly beside the tracks, and the train itself had harmlessly, soundlessly stopped a mere meter away. Giovanni's clothing was torn and stretched where new muscle growth-- prompted by the sudden absorption of so much inertia-- had strained the fabric beyond its limits. Giovanni recovered pretty quickly from that surprise, leapt easily back up onto the platform and punched the leader of the little gang hard enough to launch him into the tiled wall several meters away. The rest of the thugs departed; Gio fled in another direction before the cops could show up. As soon as he got home and started to calm down, some of the effects started to diminish. But while the experience was still fresh in his mind he started scribbling out ideas for a costume...
Since then, Giovanni has been roaming the rooftops at night. He has plagued gangs and other criminals as Slingshot, turning their own weapons against them and making a grand, chaotic disaster of many of their schemes.