If you own the emotion to the point where you control it, and it has no hold over you, you can summon it at will and combine it with anger. The look on your face is enough to be able to have anyone leave you alone, or even run for their lives to get away from you. For example, while on vacation, my wife wanted some take out food from a restaurant in a bad part of town. There was no good parking available so I pulled over on the side of the street (right in front of the restaurant), put the 4 ways on and stayed in the car with the kids while she ran in to get her take out. When she came out, within the 10 steps or whatever it was was i could hear someone yelling I looked around but couldn't see where it was coming from. I saw my wife and unlocked the door, my wife got in and said some homeless.guy was yelling at her, calling her a whore. She didn't even get to finish saying that when I heard the handle of the back door opening. I swung my head around and saw a bum trying to open the car door, and my daughter pulling the door to keep it from opening. Instant hatred and anger were on my face. That fucker noticed me looking at him iand in the fraction of a second it took me to turn around, take off my seat belt, open my door and get out he was running. I managed to yell out "you're dead" and was about to start running after him to end him when I heard my wife say "he's gone, and there are cops just down the street". The threat is gone, I turned off the hate and anger and was calm, got back in the car, locked the doors and drove away. Like any emotion, it has its usefulness as long as you control it and it doesn't control you.