The doctor went over to table filled with many strange looking devises. Picking up a pair of odd looking helmets he placed one on the know unmasked Batgirl’s head. He adjusted some dials on it before he placed the other on his head.
The two helmets were a transference device. One was a transmitter and the other a receiver. The device had many uses you could sends thoughts into the recipient changing their thoughts , views, memories, etc. You could also swap personalities
with someone. Evan replace a personality with another. Essentially erasing the original.