Ok, it sounds like things are moving a bit too quick for these guys, especially if Wege is hyped up enough to seek them out and harass them. This suggests that he is not adequately desensitized to the others existing in this territory yet.

As I am sure you can appreciate that unlike dogs, cats are not pack animals (they are like little tigers, not lions). If they were back in the wild, they’d tend to keep and hunt within a territory and do so alone. And to that end, a cat will set up their territory with their resources (food, water, warmth, bed, you) and not appreciate a new cat wandering in and encroaching on their turf. (And since the new cat has to accept that this is his new territory, they will often try to take over the house as their own territory).

Feral and outdoor kitties will naturally choose to spend a large portion of their time exploring, wandering around, and defending their territory alone. These cats only rarely interact with other cats, and in fact avoid interactions as much as possible. So, with this in mind for the normal state, it makes sense that introducing a new cat to your cat's environment can be difficult and problematic. And while its always easier said then done, it takes patience and perseverance.

First key, the patience element. The introduction must be gradual. And even after they are introduced it might take a long time for the cats to accept one another or consider being friends. And just like some people (with certain workmates or roommates), some cats might never become friends. Some cats will just not gel, and get on with one another. And in some cases, this will be rehoming the new cat. That said, I don’t’ want you to dash your spirits, but I do I want you to have open eyes (and be ready if the road to kitty introduction is bumpy).

Admittedly, the reactions of Wege are not a good start and does make this an uphill battle for us. As well, as I mentioned we don't want to put Wege or any cat in a carrier around the others, because the cat in the box will feel vulnerable and be even less likely to consider other cats positively in that circumstance.

Ideally, when first introducing kitties you want to take it very slowly. To do this, its usually best to introduce the kitties by just allowing them to smell and hear one another (but not see or harm). This is usually done via keeping your kitties in separate rooms with a door closed between them (as you have been during the day). This is to let the idea of sharing their ‘territory’ with another cat sink in. It also gives you a feeling on how tolerant the cats are going to be with one another (as overzealous attacks at that point would be a negative prognostic indicator for success). We usually do this for about a week before moving forward in introduction.

It goes without saying that during this time, each cat should have their own set of resources (food, water, litter box, a place to sleep) in their areas. This way they have what they need and don’t have to worry about the other cat stealing or compromising them.

Once they have an idea of one another, put their food dishes near the shared door, as it allows them to spend extended time with one another without a threat of attack or need for establishing their rights to be there. This also creates a positive association between food and the other cat's scent. When the cats are eating comfortably at the door you can start introducing visual contact.

Allow gradual visual contact by opening the door a crack. The door should be secured to avoid any impromptu steps backwards in their introduction. It is not uncommon for cats to hiss at each other initially, but if you are still seeing, but extremely hostile behavior at the door, then close it and leave them be for a few hours. Afterwards, try this cycle again until they are desensitized and seeing one another is no longer a stress warranting aggression.

When they can look at one another calmly, the door can be opened wider. After the cats can look at each other without hissing or becoming agitated, open the door and let them meet while you watch from a distance. If problems occur, then it’s a step back and Wege should be returned to his room and close the door. Gradually increase open door time until the cats are comfortable with each other. Keep the room available to the new cat so he still has a safe place with his own resources.

Once you get to a peaceful existence between them with this limited interaction, you can start letting them share the house while you are home. Still make sure they have their own resources and that they have access to their cubbies (ie. kitty tent/bed/etc).

To help with the general stress of introduction, there are tools we can use to help provide a general peaceful environment for our cats while they are adjusting. Often we will use Feliway (also known as Comfort Zone (http://www.petcomfortzone.com/cats/products.html) in the pet stores), which is a synthetic cat pheromone that helps to relieve stress and promote relaxation of the stressed cat. This can be used as a spray or a plug-in diffuser. There is also a diet on the market called Calm by Royal Canin. This contains a number of supplements that have been found to provide stress relief to cats. As well, there are nutritional supplements available from the vets, like Zylkene, which use a casein protein to soothe these hyped up cats.

Overall, we are asking cats to go against what is their inherent instinctual nature. Therefore, while some cats are laid back and accept other cats readily, these are the minority. Rather most often we find that introducing a new cat is a challenge but hopefully by modifying their interaction and helping make the introduction as calm and stress-free as possible we can help the kitties accept the idea of sharing you and their lives with another cat. I would consider taking a step back since Wege is still quite 'excited' (rather then desensitized) to the other cats in the house and going slow as I have outlined above.

I hope this information is helpful.
Please let me know if you have any further questions.
If you don’t have any further questions, I would be grateful if you would press the wee green accept.
Thank you,