HELP!! Need advice!

I have two 5 year old cats. Storm and Rain. They were born in the same litter and have grown up together. They have been in and out of shelters. I hate to break them up but Rain treats Storm so harshly that I'm seriously considering giving him away. What kind of effect could this have on Storm?

Are they both spayed or neutered?

In what ways does one cat treat the other one harshly and under what circumstances?

Yes, both are spayed and neutered. Rain will bite Storm out of the blue and it really hurts Storm. When I am home Storm will stay by my side. Sometimes Rain will bite Storm on the neck and drag him.

When did this behavior first start?

It's been happening these past few months.

I note that you have been asking this same question in different forums for the past three weeks.

Have you tried separating the cats as someone suggested?