Okay, here is the NineMissy propaganda. I'm putting it under the cut because it's LONG :)
So you’ve got Missy “I need my friend back” and you put her with post-war PTSD ridden Nine who feels so alone. Of course they’d be a good match.
We start about half-way though Nine’s TV series before we introduce Missy. He’s starting to heal, found someone he cares about but she’s so human and that means he will have to face loss again one day. But he’s already so attached to her.
He’s found (he thinks) the last Dalek. And with that gone, he’s truly the only survivor of the Time War. Except then he picks up another signal, one that’s too tempting to ignore. He’s certain it has to be a trick – someone has stumbled on some Gallifreyan tech and got it working again. But he has to know for sure. And there she is. He’s quicker on the uptake than Twelve, I think, at least on the Time Lady part. He’s not the only survivor.
He’s not exactly surprised when he works out (or she tells him) who she is. After all, if someone else was going to make it out, who else could it have been? Who else would go to any length to survive?
When Missy offers him an army, though, he’s horrified. It takes him straight back to the war where he broke all his rules. To the day where he said, “No more” and ended it all. But also to the way Rose had reacted when he faced that Dalek and it brought out all the worst parts of him. Even at the height of the war he never wanted an army, so why would he want one now? He turns her down, and it would be so easy to justify stopping her for good. Rose and Missy might even both think he’s going to. But Rose isn’t Clara. Rose isn’t demanding that he do it – in fact Rose, who was sympathetic to a Dalek, who stopped the Doctor from killing it, encourages him to give her a chance. Missy wants her friend back? Well, she can prove it by changing her ways. And, of course, that’s no way he can resist that temptation. And besides, he couldn’t have done it... he can’t be the only one again. He just can’t.
So, you get Missy added to the TARDIS team. Maybe the Doctor tries to pressure Rose to leave because he knows how dangerous Missy can be and he’s not so naive to believe instantly that Missy really means it when she says she’ll try things his way for once.
Despite it being her idea, there’s definitely undertones (overtones) of jealousy from Rose, because she’s not blind – she can see there’s a long history and feel the tension between them.
They meet Jack. Missy clocks Jack as a con artist pretty much instantly (you don’t spend centuries doing all the things the Master has done without picking up vibes from people doing suspicious things!) But she’s not ready to play the Doctor’s game just yet, whatever she might say. So she doesn’t let on – maybe she thinks she can get the upper hand if she plays them off each other, maybe she tries to get in on the con for the fun of it/ to annoy the Doctor. (When Jack reveals to the Doctor, she definitely over-acts being shocked)
I think we get some extra adventures before and after Empty Child/Doctor dances – the sort of thing that I really wanted from S10. Missy travelling with them, being morally ambiguous but seeming to slowly change. But you’re never quite sure how much of it is real.
Boom Town gets interesting – there’s already some great themes of the Doctor’s guilt vs condemning Blon for what she did. But throw in Missy who DID do all those things and DEFINITELY not for any reason he can write off as being justified like he can his own actions in the Time War. He’s giving Missy a second (okay definitely WELL past second at this point) chance while at the same time writing off Blon as criminal who can never change and the worst part is, deep down, he KNOWS he is. When he’s proved right about Blon, there’s definitely tension between him and Missy. Can she really change? Is giving her a chance really a good idea?
Then the Finale. Of course, Missy gets pulled into another game show. But the Doctor’s not worried about her. She’s found her way out of worse scrapes. He and Jack go after Rose. But they’re too late. The Doctor is already upset. Then realises that Missy hasn’t joined them yet. They’re being restrained and he asks after her. The screens are switched to whatever show Missy was in just in time to see her ‘disintegrated’. You thought Nine lost it over Rose, but this is far worse. Because now he’s lost both of them. And maybe for the first time Jack realises just how dangerous the Doctor can be too.
On the other side, you see Rose and Missy face off against the Daleks and this is the first time Rose has ever seen Missy actually scared of something – think Missy in Magician’s Apprentice when she realises they’re on Skaro and she can’t quite hide that fear. And that was a Missy who knew Daleks were involved. The Master ran from the Time War after seeing the Dalek Emperor take control of the Cruciform and here she is face to face with not just the Daleks but the Dalek Emperor reincarnated. She’s quick to hide it. She can’t be showing that sort of weakness. But not quick enough. Rose is scared too, of course. But she stands her ground.
Maybe Missy tries to make a deal with the Daleks (I mean it’s pretty much her default go to plan!) or maybe for once she actually trusts in the Doctor. He destroyed them once he can do it again. And he’s gone full oncoming storm after believing, even if only for a short time, that Missy and Rose were dead. Missy can see it in his eyes, hear it in his voice. She whispers to him, quiet, seductive, encouraging him to wipe them out all over again. They can do it together. It’s their right, to rid the universe of the Daleks once and for all. No one is safe while even one of them survives. They’d be doing everyone a favour. And wouldn’t it make him feel better? They work together. They always worked together well, their skills complementing each other, and they both have a knack for cobbling together machinery out of scrap – Missy is particularly good at ones that destroy things.
I feel like Nine probably tries to get Missy into the TARDIS with Rose. To send them away. It’s a risk because he knows how dangerous she is, but maybe Rose can make a difference like she did for him. And he already knows that he doesn’t have time to refine it. Perhaps he even thinks/knows that setting it off will wipe out anyone left on satellite 5 including him. Maybe that’s even what he wants. He was denied by the Moment, but he can end the war here properly this time. But Missy isn’t stupid. She sees what he’s doing a mile off. She steps out before the doors shut on Rose, sending her back.
So now both of them are stuck on Satellite 5 and they have a horrible choice to make. Missy works out how to tune the range so that they will be shielded, but they’re running out of time and it’s still going to wipe out so many humans if the range is going to be big enough to get all of the Dalek ships. Missy, of course, doesn’t care. If it gets rid of the Daleks, then of course it’s worth it. But the Doctor can’t do that again. It’s haunted him for so long. And when the moment comes, as in the show, he steps away. Coward any day.
It took me a while to figure out how it all wraps up with Missy involved. Because Rose is obviously still trying to break into the heart of the TARDIS on Earth. But she’s not here yet, and Missy isn’t going to have the same qualms as the Doctor about wiping out Daleks and humans alike. Maybe she even in some weird way thinks she’s doing him a favour by being the one to set it off. She ran from the war, but there’s nowhere to run now, and the Daleks can’t be allowed to win. The Doctor looks at her and just says one word. “Don’t” And for the first time Missy hesitates. Maybe he has rubbed off on her a bit. It wouldn’t stop her long, I think, but the Daleks are moving in, they’re running out of time. And the TARDIS knows this. Maybe she can even see how this is going to end, and that’s when she gives in, opening her heart to Rose, creating the Bad Wolf. The TARDIS arrives just as the Daleks threaten the Doctor with extermination and Missy is moments away from setting it off. Everyone stops as the TARDIS door opens. Missy is in awe of the raw power that this Earth girl is wielding. It should have killed her instantly, but here she is reshaping reality to save the Doctor.
There’s 2 main ways I can see this going.
Option 1: It’s Missy who takes the power from Rose, but it’s not because she wants to save her. (Fuck it, have Missy kiss Rose if you like! Why not?) She wants that power for herself. If that’s what can be done in the hands of a mere Earth girl, just imagine what it could do in the hands of a Time Lady! But it’s so much stronger than she ever imagined, and it wasn’t just Rose. The consciousness of the TARDIS herself was partially in control and now is fighting with her.
Option 2: The Doctor goes to take the energy from Rose. To steal lines from the Chaos Cascade: “It will kill you,” says Missy. “I didn’t know you cared,” says the Doctor. They both take on the energy, split it between them before releasing it to the TARDIS. Maybe that's enough to stop them from regenerating. Maybe it means they both do.
So there you have it. Please do with it what you will (but tag me if you do? I always need more NineMissy in my life)