all I can say is distance your self from him and when he starts to ask let him know and when he denises catch him in his rants. Tell him "see this is why we dont chill with you", after a while he will have to step it up or just relax. Ihave a freind like this, years of malnurishment, not enough schooling, and a constant desire to drink, have made him a weak soldier. But when ever we wana start a fight we just send him over to the enemie/oponents to make conversation and like clock work within 5 minutes they wana killem.