Stepchild with oppositional defiance disorder

Hello to everyone this is mostly just a vent post\seekng advice because I'm getting at to the end of my rope and need to decompress\see if anyone has any advice.My step daughter 6 has ODD, and I would put it on the major side of things. She will constantly demand whatever she wants, and until her demand are meet she will likely repeat the question for a good 30 to 60 minutes. If you try to enforce any kind of discipline she will shut you out completely like you aren't saying a word, and repeat herself again until the point she's screaming at the top of her lungs. If you try and walk away or continue the discipline she will actually start to full on punch and body slam the door and throw anything she can get her hands on. To the point she's ripped objects of the wall to throw them at the floor.An example of this is what happened tonight, She was outside and instead of coming in to use the washroom she decided to soil herself. She literally had to be dragged in, and full out refused to get changed out of the dirty clothes. When she was finally out of these dirty clothes she still refused to get cleaned up in the bath, and decided to roll on the ground getting feces everywhere with no remorse or care. It eventually ended up with a time out with a loss of TV time, So her response was to scream at the top of her lungs and ripped the mirror out of the wall and threw it to the floor. Eventually had to go in and the only communication I got over her was her demanding the TV remote and the phone it only served to set her off again. She literally cannot stop starting fights over nothing which end in absolute blowouts. And even after we try to have discussions about what happened and why within 5 seconds she's completely forgotten what we've talked about and gone back to doing the same thing that got her in trouble. She does the absolute same thing with their mother, and grandparents.Anyone else have a stepdaughter like this? Any advice that you could give me would be very much appreciated. I want to love her but it's getting really difficult because I haven't had a day without a full on screaming fit in 5 years and the bedroom door can only handle being broken by a kid so many times. X. X via /r/Parenting https://ift.tt/2VTUmXh