Prerequisites: Most of the RTD2 era, frankly.

As others have stated, The Reality War is rather... quite bad. Honestly, it might be the worst finale this show has ever seen, and that's even counting The Timeless Children. I have no earthly clue what RTD was thinking here; there are just so many elements of this episode that are atrocious. In fact, let me list some of them below:

- Why did the Rani bigenerate in the first place? There being two Ranis served zero narrative purpose (beyond giving Omega someone to eat), and the story did literally nothing with the dynamic of the original Rani being resentful of the newer one.
- Why bother bringing back the Rani and Omega is both are almost completely different from their Classic Who versions? Seriously, the Rani here is not at all some amoral scientist. She's just a random Time Lady villain, and could've been replaced by Missy without much rewriting. As for Omega, I trust I don't need to elaborate on why making him a big CGI monster was a bad idea.
- I had many logistical questions throughout this episode: how were implanted UNIT chips advanced enough to break through the 'wishes'? How was Rogue able to message the Doctor, and even know what was going on? Why didn't the Rani just wish for her ability to procreate back?
- Why does this episode expect me to care too much about Poppy, who literally didn't exist before this episode? The entire script seems desperate to make her the center of the story, when I simply could not care less.
- Plus, I really hated what RTD did to Belinda as a character. The person from The Robot Revolution who would talk back too the Doctor (and had dreams of her own), is now completely gone. In her place, is a single mother who was given a child without her foreknowledge or consent, and then had her reality rewritten so that she was always a single mother. That is just a... gross writing move.
- It's pretty obvious where the reshoots happen, and it's clunky.
- WHY IS BILLIE PIPER THE NEXT DOCTOR??? (assuming of course, that she is). Admittedly, I think Piper has the talent for it, but at this point, I don't trust RTD at all to actually write a good episode featuring a Doctor who happens to look like Rose. It's an awful, fanservicey casting decision that does NOT bode well for the creative future of the show.
- Why did Susan literally get to do nothing this season? She was teased a fair amount, and Carole Ann Ford is getting up there in age. I hope she gets to have a proper role in an episode before she passes.

To be fair, I did genuinely enjoy the Thirteenth Doctor cameo. It was actually rather nice and sweet, and I appreciated how it respected her era. Still though, this episode was just terrible. In all honestly, I've never felt this depressed about the future of the show. Even during the Chibnall era, I was at least reasonably sure that the next Doctor would at least be different. Here...who's to say? I no longer trust RTD to write good Doctor Who, and that makes me sad.