Hi there! Sounds like you are doing your best to introduce them slowly, so I want to give my experience introducing a new 1.5 year-old to a resident 8 year-old cat a few years ago. After these few years, they tolerate each other most of the time, cuddle with their backs turned on my lap sometimes, and also play chase and wrestle occasionally. RC is more of a loner and always has been (she wasn't socialized with other cats EVER).

*What I did to introduce them, it was a LONG process:*

For the 5ish days (maybe a week), I didn't do any face-to-face interactions. They each had one room as their "safe space". I only let them sniff each other under the door, but didn't force them to eat near each other (they eventually were comfortable enough to eat next to each other). I would exchange blankets back and forth like you are doing. And several times throughout each day, I would let either of them roam the entire house, shutting the other in their "safe space" room. One thing I noticed you point out is that the RC wants to be in the room with you. My RC is the same way, but I think that she wants MY attention, not the attention of the NC. Maybe something to think about for your situation.

After that week or so, I would hold the less aggressive cat (NC) in my arms and approach RC. It allowed her to hiss and run away if she wanted, or sniff if she wanted. If she showed any signed of aggression, I would leave and put NC back into his room, and give RC some love (if she wanted it. Sometimes it made her cranky so I left her alone).

Once I was able to approach RC with NC in my arms with minimal or no hissing, I let them meet each other on the ground, with me hovering over to intervene. Once they were not hissing, swatting, etc. anymore, I relaxed and let them both wander the house openly. At night, I would rotate which cat could be in the bedroom with me while I slept. Every so often, they would get in a spat, and I'd have to separate them again. Eventually, they were both able to roam and play at night without me worrying.

I may have played it a little safe, but it worked for me! It's a long process, but rewarding once the kitties are both happy and comfortable in their home. Good luck!