<human>: So my year old girl kitty, Nala, and I moved in with my best friend and his 6 month old girl kitty, Hans, just a few weeks ago. Everything started off fine and dandy until Hans started to become very territorial. My cat, Nala is skiddish and she doesn't like any cat she's relatively unfamiliar with anywhere close to her. At fist, Hans would bounce around and try to play with Nala but Nala wanted none of it. Shed hiss, get in a defensive position and growl loudly at Hans to get away. This seemed to be no problem, theyre working out things on their own.

 But recently the behavior is getting worse. Hans will attack Nala when she hears her in the litter box, Hans will scare Nala anytime she pokes her head around the stairway. Nala will want to come and lay with us on the couch and Hans will come out of nowhere and scare/chase her away. She'll kick her away from her food dish when she has her own. This kind of behavior is getting very frustrating because my cat is stressed and obviously unhappy living with a cat who won't even let her downstairs, or let her peacefully eat/poop. And all of this is happening while we are here, I can imagine it's just as bad if not worse when were not around. 

I've tried scruffing the menace cat as soon as aggressive confrontations occur between the two because I know for a fact that Hans is the instigator and approached Nala. I dont know if it's working at all. 

My year old cat Nala has been spayed while the bully, Hans is going to get fixed in a couple days. Will this help any? How do I get Hans to stop being a bully and allow Nala to enjoy the house? It's not fair to move Nala out of a safe/unstressful environment to somewhere she gets pounced on and chased away constantly. I want this terror of a cat to stop being territorial and leave Nala alone when she comes down to greet us.

Summarize the given text in a few sentences.
<bot>: Territorial kitten won't let new cat enjoy the house. She'll scare the new cat away any time she sees her.