Christian Bruckner, the man believed to have been involved in British tot Madeleine McCann’s 2007 disappearance, may spend the rest of his years behind bars if he is found guilty of the five unrelated charges of rape and indecent assault now against him. A new report described the convicted sex offender as a “twisted loner” who picked fights and stirred up drama long before he made international headlines, RadarOnline.com has learned. “He spent a year talking about me behind my back. He would not stop making nasty comments,” the ex-pupil, per Daily Mail. In his younger years, Brueckner had bee…