Why would a women mask who she really is to lure in a nice guy?

Like honestly I feel broken from the relationship I was living, caring, nice always did thoughtful things for her. Always talked about how her day went with her. Was by her side with health related things. She was verbally abusive calling me names such as stupid motherfucker or a bitch, she was physically abusive because I didn’t do something when she wanted me to do it she smacked me in the back of my head. We were playing nba 2k once she was losing so she got mad and smacked me in the head. I also tried breaking up before with her and I wasn’t allowed to cause her sister threatened to kill me so basically she was the only one allowed to break up which ultimately did happen. Why did all this happen to me

Why would a women mask who she really is to lure in a nice guy?
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