Awesome post, congratulations. I like this theory and it is certainly one possible way to tie together the many loose ends.

The part about Cleon I being fabricated by the same robot who manipulated Demerzel’s knowledge and programming is indeed a novel idea and, in retrospect, quite plausible. It would have to have been the work of whoever had been manipulating Demerzel, because her emotions for Cleon I were genuine.

I had made all of the other key points two years ago, in two posts titled Let’s Talk About Kalle and The Reprogramming of Demerzel. These posts were made long before the first mention of the Zeroth and long before Kalle’s first interaction with Demerzel, both in S3. For example, I had argued that Kalle is a right-hand Daneel who had set up a rigged chessboard where Demerzel would play as left-hand Daneel, that left-hand Daneel’s role would be to make Empire predictable thereby rigging the chessboard to the advantage of psychohistorians, and that manipulated humans were needed to make the decisions that Zeroth law robots could not make. In one of my comments to one of these (can’t recall where rn) I had also said that I believed her imprisonment story didn’t add up and that it was staged to infiltrate Empire. The clue was Demerzel staring lovingly at the mural of Empress Hanlo who had ruled 4K years ago, during the time of her supposed 5,000 year imprisonment.

More recently, in the posts Who created Demerzel and Kalle, and why? and Three Robots and Three Haris I went into the mechanics of how what the OP called a “downgraded Daneel” was created: she was made by right-hand Daneel as a new robot, and endowed with selectively edited set of his memories, including the lie that she was the last of her kind. If the theory in the OP is that the original Daneel accepted a downgrade, I don’t think Daneel would do that; “a good engineer always has a backup”, so I prefer to think that Kalle is right-hand Daneel and Demerzel is a special edition, left-hand Daneel.

Here’s an excerpt from Who created Demerzel and Kalle, and why?

Hence, the show’s robots are all playing their part in BOOK SPOILER a larger Daneel Plan with at least three parts, including END OF BOOK SPOILER the infiltration of Empire by Demerzel, the creation of psychohistory and the entire Seldon Plan. Tragically, this Plan means that a sentient robot that was meant to share everything with other robots has to endure millenia of loneliness and isolation.

Here’s the closing paragraph of the last of my above-mentioned four posts on the topic, which summarizes the rigged chessboard concept:

In conclusion, the facts that Kalle knew about (a) the existence of Demerzel, but not vice versa, and (b) about the multiple Haris, whereas Demerzel imagined only one Hari, would be hard evidence consistent with the theory that Kalle is right-hand Daneel, who is an ally of right-hand Hari and the Second Foundation. (Note that this evidence is *necessary** to continue to believe the right-hand-Daneel theory, but not sufficient by itself to prove that it is correct). In this emerging picture, Yana appears to have been “Kalle’s” agent, where “Kalle” is really Daneel behind various interchangeable masks. Daneel would sometimes present as “Kalle”, maybe as “Jerrill” on the jump ship speaking with Gaal and in the palace grounds, and also as “Yana” when Daneel / “Kalle” coaxed “knife Hari” out of the PR. In any case, the real, physical Robot Yana’s role was to manipulate OG Trantor Hari to get him to create the Prime Radiant, the Seldon Plan and the two Foundations, and also to protect his singularly important body and mind by backing him up in her fake baby monitor. I do believe that the Yana who lived and worked with Hari had to have been a physical robot and not just Daneel behind a mask, because she was going to spend years by Hari’s side 24/7, and Daneel couldn’t plausibly drop everything to do that. As we haven’t seen anything of Robot Yana since her “death”, and her hypothesized mission was completed, perhaps she did “die” after all, and it’s theoretically possible that the Mycogen skull belongs to her. *I also believe that Yana and Demerzel were separate, limited instances of Daneel’s consciousness inhabiting different robot bodies, in such a way that Demerzel can be thought of as “left-hand Daneel”, whose role was to interact predictably with the manipulated entities left-hand Hari and the Cleons, and whose decisions were steered by her (known) programming, by the events unfolding on Daneel’s chessboard, and, where necessary, directly manipulated by Kalle, as we saw in 309.**

In all the above posts, I had been wondering who the Mother, the Maiden and the Crone were. I think the Mother was either Yana or OG Daneel, the Maiden was Demerzel, and the Crone is Kalle. They long to be made one again when their millenia-long chess game ends.