Help me please!

Ok, I posted this question 2 times in the water sprayer thread, and still no answer, so I figured maybe I would get more attention asking it in a whole new thread. Ok so here it goes:
I have a major problem with my boy Neko, and my baby girl Mia. Neko is 1 years old and neutered, Mia is 3 years old and spayed (although she had panleukopenia (sp) when she was a baby, right before her scheduled spaying, and was knocking on deaths door, she lived through it, but had to wait to get spayed, she snuck out, got pregnant, and then gave birth to 2 of them (one was alive, one was stillborn), she was still carrying 2 others and had to have a c-section. She wouldn't feed the babies for a couple days but finely did, all have great homes now, 2 living together on a farm, 1 at my friends) Ok that is the background on them, so here is the problem.

Neko and Mia were fine when he first came home, although once we adopted Onyx into our home, Onyx started bugging Mia (chasing, hitting). Well Onyx stopped doing that, and Neko started. Although when Neko does it, it is horrendous, he chases her down, then pins her down, with tons of evil growling and hissing, and lots of fur flying. I have found her hiding under tables with scabs on her nose. So during the winter she lived in my room, and now she lives in the garage. She will NOT come inside unless I am holding her very close to me and she is under a blanket, she is a very shy cat anyways, but she only feels safe in my arms. I have tried spraying Neko (towards the back end), spraying somewhere near him, and hissing, and of course yelling once because I was so scared he was going to hurt her. I never hit him, but I really don't know what to do. He totally ignores everything I try and do to make him stop this, he could care less!!! When we move, Mia will have to stay in the house, and I really don't want to have her locked in a room. (Can't lock Neko in one, last time I did he tore apart my room and pulled up my carpet)
So if anyone has any idea on how to make him stop attacking my baby girl I would really appreciate it, plus he is starting to teach Doku this bad behavior!

Last time Ophelia came home from the vet, for some reason Trent didn't recognize her and there were some scary noises and posturing. Hissy gave me the advice that if he went after her (luckily he didn't, we separated them before anything happened...) to throw a blanket over them. Honestly I don't know if it would work in the long term, but it's a non-threatening way to get him to chill out on Mia. If it happens often enough, he'll make the connection that this scary thing (the blanket) happens when I attack her!

I assume that you have had Mia checked by the vet? Many times cats will sense sickness and attack the weaker cat, even when we don't see anything wrong. They are very good at masking pain.

Yeah, I need to take her back to the vet though to get updated on vaccines. I don't know if the blanket will work (he likes being under blankets) but I will try it next time he goes after Onyx (he loves chasing onyx and pissing him off, it is funny cause Onyx gets mad just because Neko looks at him), so next time Neko goes overboard with Onyx I will try a blanket or towel. I don't want to try it out with Mia, don't want her to get hurt. Thank you for replying so fast!

How many cats total do you have? It sounds to me like you have might have to many cats in a small area? I would start adding cat condos, and cat shelves to create more secure spots for the cats. You surely do not want your one cat hiding in the garage for the rest of her life, so I would also look into the Bach Flower remedies, even talk to a cat behaviorist. Also check your PM's-

Thank you hissy, I am sending an e-mail to Wendy. We have 9 cats, but quite a large house for us (over 1400 sf, only 2 people living here) We have 2 extra large cat trees (saving up for another) we also have a cat condo, and we open windows during the day as well for them. My desk has been converted into a huge cat bed, lol, with fleece blankets and stuffed beds. We also have a very large ottoman that they take over, and a love seat that they have if the dogs aren't in. 4 of them are allowed outside, but only 2 of them really go out (Mia and Princess). Also, the cats are allowed in every room at all times (except one bathroom because they steal drain coverings). Tomorrow I am going to make an appointment for Mia, just in case!

Oh also, the garage Mia is in has a dog door on it so she can go into the backyard, although she doesn't do that much.

Is there a way to contain the attackers instead of the victim? I was in the same situation once and I isolated the victim and now wish I had isolated the attacker. It's OK because "Victim" retreats to his upstairs whenever he feels the need but now, Attacker also has been sneaking up there.

Well last time I locked Neko away he ransacked my bedroom, pulled up my carpet, and peed and pooped on my purse (wasn't sick, just mad). Even though there was a litter box, food, and water in there. Plus even when Mia was in my room, she only wants to be outside, she never did like it inside. Neko won't let Mia retreat, no way no how. I always have to pull him away. I might try the vanilla trick and some others as well, I just wish she would use the claws and teeth she has! She needs to fight back to show that he is not the boss!