Koenma:  Sacred Energy is the highest echelon of power that any being can harness - but how COULD you ? It takes forty years of discipline , at least .
Shinobu Sensui: Forty years shared by seven personalities is only _ six _ . Of course , even the training 's no guarantee . You need to be receptive to it , having the inherent desire to correct the world around you - something Genkai discovered she did NOT possess .