How to make my brother less violent?

There are four children at home, including me. They are brother, sister and little sister. My sister and I are a family, and my brother and little sister are a family. Although they are two families, they often come to our house to play. We don't live at my mother's house, but at my aunt's house with my grandparents.

My younger brother, like my sister, is in Grade Five this year. Average academic performance. My brother will go to Taekwondo during the holidays, and my little sister will go to ballet class.

so I lost to them from my skill.

but I don't think my brother should go to taekwondo. Of course, I didn't say that Taekwondo was bad. Just because I found him violent.

He often punches and kicks his family, punches his arm and kicks his leg, especially when I don't agree with him to do something, he punches me. . But I really dare not hit him at will. My grandmother, aunt, grandfather and others will protect him, saying that he is still young, and you, as a sister, have to let him go. (no matter my sister or any child)

I really couldn't understand at that time. Why should I let him fight?

Besides, he has a bad temper, and he often yells at his elders, but they just say a few words, who is willing to hit him? My brother is the only boy in our family, and my grandfather is also a bit patriarchal. But fortunately, my aunt is sober.

especially today, when I came home from class outside. My sister and my brother are still running around the house. They make the house where grandparents live messy and the living room is messy.

They filled their gloves with water and sprayed it everywhere. I told them to clean the living room and house and restore it to its original state, but they didn't listen to me at all. I can't help it. I can only threaten them with a clothes rack, and they will do something.

Then, when my grandmother came home, I wanted him to take care of them, but my grandmother asked me to clean the living room, saying that I was asking you to work. Why didn't you do it? Then my sister, who had just taught her younger brothers and sisters a lesson, became a joke in their mouths.