I would begin by just putting the carrier in the room while Kenobi is nearby but not in the room. That way, Kenobi has the option of going in or not going in. If Kenobi doesn't go in at all or leaves the room promptly, I would still leave the cat in the carrier for 10 mins or so anyway just the...
It might be worth a try. It seems like you have done everything else possible. When we did this method the last time, we introduced a kitten to an existing cat. We put the kitten in my daughter's bedroom with a kitty litter box and food and water and that is where he lived for the first two...
If you haven't tried it yet, I would try putting Kenobi in a carrier or crate and put it in the room where one or both of the existing cats are. That way, the existing cats can get used to the new cat in "their" territory but without any threat. Just do a 10 minute session at a time or so. Then...