His second secret was along the same vein as his first, a type of superpower, but it was much more sinister and practical in nature. If he wanted, he could control anyone's mind to do certain things or say certain things.
However, the period of control would not last for very long, it was generally only a minute. The person who was controlled by him would have temporary amnesia after breaking free from his control. To put it simply, that controlled individual would not know or remember what happened during that one minute.