Regarding why Palpatine goes from wanting her dead to wanting her to kill him and take his place, I think he changes his plans after Kylo turns, make him unusable. So he decides to use the Resistance fleet to goad her into killing him so he can possess her.
Alternatively, the whole thing could be Palpatine wanting to choose the strongest vessel. If Kylo kills her, it kills two birds with one stone. If Rey kills Kylo, she’ll still come to him and have proven herself stronger. So when she faces him he could say something along the lines of this (if possible), and then use the fleet to force her hand.
For Rey’s identity, I basically think there are three options, ranking from most preferred to least:
• She is no one.
• She was created by Palpatine.
• She is Palpatine’s biological granddaughter.
If we are stuck with Rey Palpatine, maybe we could explore ways it could be better set up throughout the trilogy. The one interesting thought I did have is that if Rey is a Palpatine but we had Ben Solo survive, a Palpatine and a Skywalker creating a new Jedi Order together could be an interesting implication that this new generation of Jedi will be different, along the lines of what Outbound Flight said.
I need to think more about the actual moment of Palpatine’s death, but I do agree something needs to be altered with it. I think it would be funny if he said, “I’m all the Sith” and she said, “I’m no one.”
Does Poe voice his character in the LEGO game? If anyone says something about contuing the fight, I think it is most appropriate if it is Poe.
I think it would be interesting if Rey’s outfit was half white, half black throughout, sort of like Snooker’s mock-up of Obi-Wan’s robes in TPM. And if Ben survived and showed up in the final scene, maybe he could have a back/white outfit as well. At the very least, this could be applied to Rey’s costume in her final scene, symbolizing that she has accepted both the light and the darkness in her.
Speaking of the ending, here is my very radical outline for an alternate ending of TROS:
We cut away from Rey and Ben before he dies. Rey joins back up with the Resistance and they celebrate.
Fade to black on Celebration.
Fade in on shot similar to first shot of A New Hope. A Resurgent Star Destroyer flies overhead, followed by dozens of Resistance ships chasing it. At the front is a modified Blockade Runner, in the control room sits Poe Dameron. (Or possibly leading the chase in an X-Wing that Poe sits in with BB-8. If he is in his pilot suit, change the color of his jump suit to blue New Republic colors.)
I feel him being on the bridge of a ship would clearly visualize his transition to hotshot pilot to responsible leader, but he was still flying an X-Wing during the end battle. Anyway, this could be the moment Poe says something inspirational over the comms that could also help emphasize “General Poe”.
[This would require a fan-film scale production, but I think it is rather straightforward idea-wise]
On the outskirts of a rural village, locals gather outside as three First Order troop transports land nearby. The bay door opens, but instead of stormtroopers we see rescued children rush toward their emotional families. After all the children are out, we insert footage of Finn standing behind them (Potentially either Luke or Leia’s lightsaber is attached to his belt if you keep his Force subplot). This would reflect nicely with how we are initially introduced to Finn, and would bring his arc full circle.
Bonus Idea: Have Chewie finally go back home to his family on Kashyyyk. You could just create a modern version of this image, have Chewie step into frame, then cut to a close-up. Chewie deserves more than a goddamn medal at this point!
Finally, we get to Rey. She flies across the dunes of Tattooine and lands outside the abandoned Lars homestead. R2 and 3PO are with her, and still-wiped 3PO says there is something familiar about this place. Rey briefly explores the home, then sits outside and unrolls a cloth full of saber parts. In an insert shot, we see as she uses the Force to construct a new lightsaber. She activates the saber to reveal a yellow blade.
She then senses something ahead of her. The twin suns slowly rise above the horizon, and with them, a silhouette of a figure rising over the hill. It’s Ben Solo. Rey smiles and rises to meet him. The spirits of Luke, Leia and Anakin watch from a distance. Our final shot is of R2, 3PO, and Rey watching the sunrise as Ben slowly approaches.