5 year old saying weird things

My five year old for the most part can be an angel. Super high energy and just crazy active. Lately literally just since she’s been five has had a hard time listening and saying the craziest things. I’m not sure if it’s bc we moved near her cousins and they watch action gore movies. But she would say I’m going to kill you mom, I’m going to scratch you and see blood, etc. I keep telling her that’s not ok and she’ll mostly say these things when she’s in trouble or angry at her older sister. She also sometimes answers herself. For example she would say let’s go get some milk followed by ok let’s go. Can anyone relate? Besides these weird tendencies she’s super affectionate, talkative, polite to strangers, and listens. I’ve observed she seems to do the odd behavior only at home.