Only when one has personally experienced the evil he has done and experienced the pain, can he be qualified to ask for forgiveness from the victim. Otherwise, what he deserves can only be the judgment of fate, not light forgiveness. Forgiveness is only available to sinners who are cleansed of their sins or who accept an eye for an eye.
If Chrollo is not afraid of death, nor is he afraid of losing everything, nor is he unrepentant, just like a devil living in a human body who only laughs at the insignificance of mortals, then how can Kurapika make him kneel down willingly and accept the trial for his sins? This seems to be a war in which he kills eight hundred enemies and loses a thousand, but Kurapika has no other choice but to make such a desperate move.