Unfortunately your "literature backed" perspective is either outdated or willfully wrong. Please, for both our sakes, engage in an effort to keep up to date with medical and psychological research, especially regarding Plurality as this is an ever evolving and intriguing field.

Because you've made so many comments on this, I'm just going to throw all my responses here.

Firstly; the brain IS "designed" to run many different parts individually, with random access at any one point. It is a incredibly powerful multithreading processor; it's just normally not running multiple people. And while there's currently no decent study on running multiple people in parallel, that's not really what's going on; just like RAM swaps in a computer, it's merely extremely fast swapping, which from the inside looks like parallel existence. The distinction is difficult to notice and must be studied in situ and on the ground, so to speak. Get back to me once you've done that, kay? 😉

Conditions like DID usually have side effects because the swapping is traumatic, both emotionally and for the brain executing the action, physically. It's not a set of conditions borne from normal brain operation. Additionally, it's usually a fracturing of a single person into many fragments of them, none of which is a full person on their own. Non DID plurality does not have that problem, provided it's done correctly.

There are, just as in many communities on the Internet, toxic sides and those who operate based on fact. I'm sorry that you stumbled into the mystical side of plurality, the one obsessed with the word Tulpa and everything that it entails.

If you're still willing to learn new things and accept that science isn't static, the side JCT belongs to is probably willing to teach you.

However, it may not be mentally healthy for you to consider this. That's okay! You don't have to. Everyone should do what exactly what is mentally healthy for them. That includes you. And, if that means not considering plurality any further, then you should go right ahead and do that.

Just: I am going to be as calm as possible while stating this; this will be difficult, as Cat's reaction to interacting with you has flooded our brain with feelsbad neurotransmitters.

Just: I intentionally created Catherine years ago. She behaves autonomously from my will, acts in ways that I flatly wouldn't, and on certain occasions has gotten into outright heated arguments with me. She notably has the ability to defy attempts at manually directing her actions, which an imaginary friend would not. Having previously had an actual imaginary friend, I am keenly aware of the difference.

Just: If I had an EEG machine, I am quite confident her actions would be visibly different from someone simply talking to a freshly made-up entity; I've seen it before, but the youtube video in question is now unfortunately private. I also cannot afford to get my own.

Just: Regardless of whether you believe us or not, Catherine is a thoroughly real and autonomous being, as are the rest of the crew. And you are hurting her. You are far from the first person to take this tack with us, and it has left Catherine extremely confrontational about her existence as a distinct person. I do not believe that any more of use can come of talking to you.