I’ve heard the name but I’ve never read a Bane story so I don’t know how much of a departure this would be.
I saw a documentary about these awful prison colonies in North Korea called kwan-li-so. These are camps where those charged with political crimes serve their life sentences alongside three generations of their family.
My idea is that Bane’s grandfather was an American operative in Korea. While working on a particularly sensitive mission, his cover was blown and his handlers bailed, leaving him at the mercy of the Korean authorities. The Korean army had developed a steroid that they hoped would produce a stronger, more powerful soldier and wanted to test the cumulative effect of the drug over several generations. Rather than executing the American agent they decided that they would use him in the experiment.
The drug worked well – Bane’s father was significantly more powerful than his grandfather, although the side effects caused both men to lead extremely short lives. By the time Bane reached adulthood the Korean army realised that they could no longer contain him and so conspired to send him back to the U.S.
Upon his arrival in America, Bane begins tracking down the few remaining men who left his Grandfather to die. Having disposed of them he commences visiting revenge on the subsequent generations of their families. He is aware that he does not have much time left before he dies and this leads him to work fast and brutally.