Otoharo!
I would phrase this differently. As there is no karma, I would say, I chose to cut my ties (whatever they are) with this person from my past. A good visualization of cutting with giant scissors works also. As to where reiki assists, I, too, do not know. Reiki assists you in your endeavors. It is YOU who cuts the cords. It is YOUR choice. without that, reiki could do nothing. Good for you in your choice.
finality