So... let's continue.
On Princess Irulan and Chani; Well, I can't say much about them when it comes to the 2021 adaptation, as the former made no appearance in Part 1, and Chani made some brief appearances just near the end. Yet I think we can find something very interesting when we see how they were treated in comparison to the books, the 1984 movie, and the 2000 Mini Series.
Starting with Princess Irulan, the original book of Dune seems to use her mostly as narrator, as many of the quotes used in chapters have her as the author of the books, she herself quotes. She hardly makes an appearance in the original Dune as well, with most of her character development and relevance happening in Dune: Messiah. The 1984 movie follows this trend, but places her as narrator only for the beginning of the movie, where she has to give a 2-minute exposition about the entirety of the Dune universe rather than letting it happen organically. So basically, we are brought about, having to understand terms like "Spacing Guild" or "Bene Gesserit" or the entire political landscape in a 2-minute spiel, and then launched to the movie itself. Now, to be fair, this was something that David Lynch himself was against, but was mandated by Studio Executives, so I won't hold it against him.
It's the 2000 Miniseries that does something unique with her; she's actually a character, with her own wants, desires, and motivations. Though at first treated as a pawn by her father, the emperor, she does not meekly accept it, but rather resolves herself to become something more. She investigates the fall of House Atreides, she uncovers the Harkonnen plot against House Corrino (putting herself in great danger by seducing Feyd Rautha Harkonnen and discovering the actions taken against House Atreides) and becomes an actual player and someone that the emperor listens to near the end. That her first appearance also shows her more gentle and fragile side when she goes to Arrakis and speaks to Paul makes her a more complex, and likeable, character, as we can also see her grow, like Paul did, under the pressures of life, if under different circumstances.
Frankly, Princess Irulan in the 2000 miniseries is a more assertive, independent, and growing character that, much like Paul, manages to go through hardship and learns how to take control of her life. We could use this for the movie.
Chani is an interesting example n how different she's put in the different adaptations. In the Dune books she is mentioned on many occasions, and her appearances and interactions with Paul, though mentioned, are not expanded, nor given that much attention. It is clear that they love each other, but Paul's journey takes precedence over everything there. The 1984 adaptation goes a bit deeper into how much they care for each other, but then again it is also a faithful adaptation of the books. Chani, besides being Paul's companion, and a Fremen fighter, does not seem to add anything else. Nevertheless, both the book and the 1984 movie adaptation managed to make Chani a fun and likeable character. This will be important later on.
Chani's 2000 Miniseries adaptation, and the 2021 adaptation, seem almost complete opposites in a way yet both managed to expand on the character through minimal actions that made us think and made us imply more about her through them.
Starting with the 2000 miniseries, Chani's first appearance is when she surprises Paul and manages to hold him prisoner, if only temporarily as Stilgar allows him and his mother to join them. From this encounter, we know she's a skilled warrior, as Paul had defeated other Fremen before her. Through the rest of the series we don't see her fight more, even though she clearly accompanies Paul and the rest on some more missions, as the series makes a point in focusing on her more as a woman, an advisor, and Paul's companion than a fighter. That does not mean she does not fight though, as we are shown the end result of someone trying to face Paul, and she quickly dispatched him. Overall, this Chani is likeable, she shows herself as strong, resourceful, a caring mother, a counsellor, and not afraid of letting herself speak. It does play a bit too hard on the maiden in love angle, but not to the detriment of the character or the story.
The 2021 adaptation...well, we only got a few minutes of Chani, and her actions and words. Yet through them we can see that Chani is a more jaded and cynical individual than her previous adaptations. Clearly a strong fighter, and from what the trailers indicate she will continue in this trend through the second part of the movie. One of the elements shown is that she clearly shows no sign, nor desire, to see Paul join with the Fremen. Perhaps it's my imagination, but the scene where she gives Paul her knife to fight, then tells him it's so that he doesn't die unarmed (which is already quite morbid) is made all the worse as she has this tone not of disinterest, but more like vindictive glee, like he's going to die and she will enjoy it. That's the kind of thing that sticks with you, and makes me wonder how the hell are they planning to pair the two of them in the next section.
Frankly, I much prefer the Chani of the 200 miniseries, but I can see some flaws in said adaptation as well. Chani would have been better served as showing more of her skills as a fighter as well as a mother, she could also have been the one to train Paul, thereby allowing them more time together to connect and bond. Overall, if we could make it so that the 2021 Chani's skills are added to the 2000 Chani personality with the changes I already suggested, then the character would work much better.