These are general recommendations--like items of clothing in a store. They dont directly describe your former group but try them on as you would try out clothing in a store and see if any of this 'fits'
1) Prophetic Charisma by Len Oakes He surveyed 20 charismatic leaders and described their psychology. They all had a remarkable similar inner landscape and surprisingly similar life trajectories. Reading this can help de-mystify the lingering influence of such leaders.
2) [i:ede124357b]Sorcerer's Apprentice[/i:ede124357b] by Amy Wallace. Informative description of being a in a long term, secretive, 'group that wasnt a group.' Especially informative in descriptions of the way inner circle members recruited new members--done by targeting those who remained interested despite being treated to displays of rude, even abusive behavior by inner circle members doing outreach via readings at bookstores or workshops. Atmosphere at the workshops is also described.