I'm up for collaborating a backstory. Sorry it's taken me so long to post a concept. I kept changing my mind as I struggled to learn the system and build my character.

The one sentence summary: Krsnik is a cyber-enhanced crimefighter trying to make a difference in the world by protecting the innocent and inspiring others to pay forward good deeds.
Here's the more detailed summary:
Aleksander Ceh, AKA Krsnik, is a Sixth-World masked cyberavenger.

His parents, immigrants to the UCAS from Ljubljana, Slovenia, were mild-mannered megacorp employees who were killed on the dangerous streets of [insert everytown UCAS]. Determined to avenge their deaths, he tried to find a way to make a positive impact on the world. He tried charities and volunteering but was met with corruption at every turn. In a fit of frustration, he decided to take matters into his own hands.
While growing up, his parents told him of the Slovenian myths of Krsnik. The Krsnik myths took many forms, from vampire hunter (or Kudlak hunter) to fire god to benevolent magician, but they all had one thing in common: the Krsnik helped mankind in an unforgiving world. Inspired by those stories, Aleksander decided to don the mantle of the mythical hero.
Krsnik has carved out a small niche for himself in street lore. Patrolling gang-infested areas, he often drops in on criminals as they are shaking down innocent victims or staging other perfidious acts of malevolence. Some say Krsnik is one man, others say he is a team of demented do-gooders because some have sworn that they have seen the crusader cut down by their comrades. The truth of the matter is that Krsnik has managed to survive each severed limb, each lost organ, by augmenting himself with cyberware.
Nowadays, the Krsnik stories revolve around a masked man wielding a varied array of guns, blades, and a grappler. Wherever there is danger, wherever an innocent might suffer, Krsnik will be there to lend a helping hand.