Just need to rant. My cousin is a sociopath

My little cousin is 11 I believe and he’s just the most disrespectful kid ever. He’s always in trouble at school, fights girls, bullies my 4 year old, disrespects adults and when I or anyone says something he says “but you can’t do anything bout it, My mom won’t let you” and it’s true. She side with him on anything. Hes always in trouble at school and she blames everyone but him. He’s a huge liar. I saw him taking my sons toy from him and throwing it on the floor trying to break it. He’s put dirt in my sons hair. When my son was a baby he used to take his binky from his mouth and then just hide it and laugh while my son cried. So id go tell his mom and then he’d lie and say he did nothing and of course she believed him. As bad as it may sound I absolutely can’t stand him and I don’t allow my kid around him unattended. Now here’s the problem my aunt watches my son for free while I work. She always lets my cousin come over to play with her grandson and when I get there to pick up my son he has a bunch of stores to tell me about how his cousin has been calling him gay and picking on him. My son is 4 and he can’t really tell when someone is treating him badly. Like yesterday my little cousins asked to take my son out to play tag and I told them not without me and my SO watching and I told them they will have to play in the backyard Because I don’t want my son running out into the street when being chased. What does my little cousin do? While I’m getting my shoes on He takes my son out the front door as he flashes a devious smile at me. I jumped up and grabbed my son to take him to the back yard. Then I notice they didn’t even invite him out to play. They invited him out to taunt him. So I told my son to come with his father and I and we will make up a game. My sons response was “no I want to play with my friend” it’s just so annoying. He’s a pain in the ass and he gets my 9 year old cousin to follow in his foot steps. It may be a bit dramatic but it honestly reminds me of this story I saw on tv about those two very young boys that lured that toddler from the mall and killed him. He’s so evil. Is it wrong for me to feel like he’s going to grow up to be a psychotic murderer ??