I wouldn't know if he's trying to manipulate anyone into taking sides. But he's specifically targeting people who have shown support towards me. They're not his friends and I think his main interest in them is just to control his public image. He often feels shame and he copes with it by trying to redeem himself.
They're not really what I'd consider friends either. Just supportive people who have come to know about what's happening. His behaviour just disturbs me because I keep trying to distance myself from him, but it just feels like he's always encroaching on my boundaries in one way or another. But I guess it doesn't matter anymore since I'm going to dissociate from everyone there anyway.
I've never trash talked him either. Actually, I almost never talk about him to anyone (unless someone asks me about it) because it doesn't even occur to me to do so. This thread is the only place I've discussed him in much depth, in years.
Thanks for your advice. It's been quite helpful. I've already changed how I approach the situation due to this thread.