Thank you for your update, I'm sorry to hear you are still experiencing troubles with your ex-friend. It sounds like it is becoming very draining for you and has started to escalate.
I understand that you and your friends were trying your best to incorporate him into your group however, it is concerning that there has been physical and verbal harm directed towards another friend that you all had to witness. Have you discussed organising a meeting with your co-ordinator, friendship group and your ex-friend? If this has escalated and you don't feel comfortable having him around, it might be helpful to discuss how his behaviour is making you feel. It might also be helpful to understand why he is engaging in this behaviour.
I'm sure your co-ordinator is trying the best they can to help this individual out with his struggles so maybe hearing how you are all communicating to one another and giving your friendship group some tips in how to manage too might be helpful?
I hope you can find a resolution to this soon :)