I'm going to stick up for my siblings if my parents are being unreasonable with them
What makes you want to stick up for your siblings?
They are my siblings and I will stick up for them regardless of what they did to me.
It is understandable to be loyal to your siblings and want to stand up for them. You care about them and it will make your relationship better even if in the past it wasn't good.
I don't care. I'm going to beat my parents up if they try to hit my siblings because of them not listening to my mom.
I think that is escalating the situation too much. If your parents are abusing your siblings you need to get the police and CPS involved.