The 75-year-old American completed his takeover of Pompey, who had fallen from the Premier League to League Two amid financial woes, last August.
Portsmouth, two-time Premier League champions and FA Cup winners, went into administration in 2010 and endured three relegations before entering fan ownership.
"The story going down is an unbelievable story and the story coming back is an unbelievable story," Eisner told a Leaders Sport Business summit at Chelsea's Stamford Bridge, as quoted by The Guardian.
"[The owning fan group] recognised overwhelmingly that they needed somebody but they had such a bad experience that any name on any piece of paper would have been frightening.
"Luckily my name is well researched. I hadn't been to jail, not stolen any money, don't sell arms. They were like an abused child. They thought 'Oh my god, not another guy'.
"Everything I've done has been involved with storytelling and increasingly telling the story of sports. All of our sports films had one constant theme – the triumph of the underdog over seemingly insurmountable odds. This is a story we've told time and again in fiction. With Pompey, we hope to get it right in fact."
Portsmouth were promoted from League Two last season and currently sit 15th in the League One table.