Worried about my sister please help:)
He seems a very toxic personality. Nothing much has changed. He can be very manipulating and wears many masks to get what he wants. I see Jealousy, major mood swings and a victim attitude. when ever there is a problem between him and your sister he uses it to go out and indulge in wasteful empty activities.
Your sister is wearing rose colored glasses. she should have moved on from this man years ago.