Time is your best friend in this situation. That, and Feliway. Neither Mac nor Ming like Kimba at all at first. For about two months,there was growling, snarling, and actual fights from time to time. Kimba always stood his ground, heck, sometimes he was the instigator. It's been three months since I took Kimba in and things are much quieter now. I still here the occasional growl, but no fur has flown in awhile. The boys are just getting used to having him here and have accepted him, sort of. They may never be best buds, but it seems they are working it out.