So why exactly was he terrified of you?
To intimidate words alone are empty. Body language, tone and credibility that you will in fact follow through on your threat are necessary. Don't say it if you aren't prepared to do it.
Undermining people is another story. This can easily be done through passive aggressive tactics like Hyper proposed with her doubt casting techniques.
He said something bad about our son.
My ex-husband is a bully. He used to throw things and get in my face. He is an alcoholic and he is a Narcissist.As soon as I learned he would never hit me, things changed.
I stood up to a bully and took his power away. That is why he is afraid of me. Because he knows that I am not a bully.
But boy could I hurt him if I wanted to.
"Don't disobey me" "Don't disappoint me again" = i don't care or no as a response (or some arguement)
"Lie to me and see what happens" = i don't care + mention how they have lied due to remembering or documenting what they said and are now a hypocrite
"I won't hurt you if you tell me the truth" = use evidence collected to attempt to destroy their rep with their friends and/or for purpose to annoy them to show they are weak minded fools