There were three kids in my family, myself and two younger sisters, close in age. My youngest sister and I were always irritated by the middle sister. She was exactly as you described, toxic narcissism personified. The worst part? Our parents tolerated it.

The youngest and I would get yelled at if we stepped out of line even a little. The middle sister could act like the love child of Charles Manson and Lucrezia Borgia, and we would be told, "You need to be patient with her, she's sensitive."

One more reason I don't talk to any of those people anymore.