Pwbpd traits brought in aggressive stray cat - cat is outdoor/indoor

This has been stressful. They brought this cat in three years ago. Love the cat. Sometimes he’s very aggressive though. He clawed the souls of my feet where I couldn’t walk for a few days. He chases when he’s upset and I was trying to run from this cat and when I stopped to open the door to get out he completely messed up my feet. Deep cuts. Everyone in this house has been attacked by this cat at least 10 times. Pwbpd lets the cat outside and the cat comes home with cuts from fights. This cat is also getting other cats pregnant so we have a ton of kittens roaming around the neighborhood. I’m not mad at the cat, he’s just doing what cats do. I’m pissed at the owner

I’ve advocated many times for this cat to go to a vet and get neutered. Pwbpd traits flips out- tells family I want the cat dead and I’m trying to harm it. I do not feel safe taking the cat to get fixed as he’s not mine and I fear physical retaliation as that happens whenever anyone challenges him. I’m just disgusted he’s allowing this and these kittens are homeless- he knows his cat is having many kids and he goes “if you just ignore the kittens they’ll go away.”

Am I overreacting ?