Hmmm, I think this could all be a normal case of a guy who just doesn't like cats and a cat being a bit aggressive towards a potential decline in the amount of attention it recieves.........BUT....the other thing that comes to mind is that maybe they met in a past life and are/were nemeses but they aren't fully aware of who each other (or possibly even themselves) are.

In the event that one or both of them are aware of the other's identity, I would strongly suggest breaking it off with one of them. But this war you speak of....it will unfortunately never truly come to an end These things often continue on for generations and often end with the sad demise of those caught in between their competition for love.

Step one - I think you should get a hold of your local animal adoption center and tell them that you have a special case involving a cat with somewhat human reactions who you suspect to be a malice intent scoundrel reincarnate. They get this quite often really, don't worry about getting weird looks...they know what they're doing.

Step two - Your boyfriend...chances are he will know you got rid of the cat (his enemy). A man like him with an archenemy doesn't give up so easily, he will try and find your cat wherever he goes because it's just who he is. The battle began long ago.

Step three - It's out of your hands you must let both of them go there's nothing you can do to stop this and they will continue on for ages destroying relationships and wreaking havoc wherever they wander.