***MAJOR DOCTOR WHO SPOILERS***
So, that happened on Saturday. I knew it was coming, we've all known that it was coming for a while, so it wasn't too shocking. I think the most emotional part of Clara's death was the Doctor's reaction. And Me's realization of what she had inadvertently done. That said, the Doctor was directly responsible for Clara's demise.
How could I say that, you ask? Let's take a look.
First off, let's talk about Ashildr. Remember her from way back like five episodes ago? She was the innocent young viking girl with the vivid imagination, whose story telling saved her village. Unfortunately she died doing this. The Doctor, racked with guilt after Clara told him to feel that way, took a med-kit from one of the deceased aliens and brought her back to life. This med-kit had some side-effects, the main one being that it made her immortal. The episode ends with a beautifully sad shot of her standing by herself as time moves around her, leaving her unchanged. When the Doctor sees her next, a mere 800 years later, she is living the life of a highwayman, robbing from the rich and keeping for herself. We learn that she barely remembers her name and has taken to calling herself Lady Me. She tells the Doctor that while she may be immortal, she still has a normal memory span. She shows the Doctor her library, filled with hundreds of journals that she has written to remember what she's done. The Doctor reads these journals and learns that during her 800 years she has lived through and taken part in almost all the major events during those times, and even had children. Children that she lost to the Plague. A bunch of events happen, and at the end of it the Doctor and Ashildr part as people working toward the same goal differently. The Doctor is out to save the planet, and Ashildr is out to save the planet from the Doctor. They aren't enemies, but they are far from friends. When we finally saw Ashildr again on Saturday, she had radically changed once again. But I'll get to that later.
Now for the Doctor. Twelve is a very different Doctor, especially from the more recent ones. He's callous and harsh, he doesn't know how to be nice to people, and he doesn't really care. Clara has slowly been making him care: "She's my care-er. She cares so I don't have" all the way to making him flash cards on how to be nice. Twelve has gotten more "human" since his first episode. Remember it? With the ambiguous ending of did he push the cyborg or talk it into committing suicide? He learned to care about Clara fairly quickly, and he's needed her to make him care about other people. The Doctor has always been confidant, but Twelve has taken the levels of cockiness to new extremes. He knows that he is going to win because he always has. And his fake it until an actual plan forms method has been rubbing off on Clara this whole time. We've seen the Doctor become like his companions, and we've seen his companions become like the Doctor, but never this negatively before. Twelve is calm and methodical, and very often doesn't seem to care when people die, so long as Clara survives. We've seen countless people die and the Doctor not hesitate until Clara is in danger. Clara isn't/wasn't his weakness, she was his humanity. A humanity that was somehow lost in between Eleven and Twelve. This hasn't been fully explained, but I believe it has something to do with the new set of regenerations Eleven received at Trenzalore.
And finally, Clara. Clara started off as a mystery for Eleven to solve, who then stuck around after the mystery was solved. She floundered as a companion for a bit after this, probably because the writers hadn't bothered with giving her dimensions beyond "she's a mystery!", but after a few episodes with Twelve, she began to actually have a character and a purpose. She began to teach the Doctor how to care again, she began to slowly give him back his humanity. In process of this, she began to lose her own. She started to become more and more like the Doctor. She got his cocky attitude, and negligence towards other people (in a small way). She even pretended, very convincingly to be the Doctor on several occasions. Even convincing Cybermen that she was the Doctor at one point! We've seen her take more and more risks, all the while calling them clever plans. Which culminated in Face the Raven, when she convinced Rigsy to give her his death sentence because Ashildr (Mayor Me) had given Clara her personal guarantee that nothing would happen to her. Not knowing the full details of Ashildr's abilites, or the deals that Ashildr had made, Clara thought this was exceedingly clever. Something she repeatedly told Rigsy, who still thought it was a bad idea.
Should've listened to Rigsy.
The Doctor figures out that Ashildr is working for someone, proves Rigsy was innocent, and should've won the day! Only to find out that Clara had taken the death sentence. Ashildr admits that her personal guarantee of protection won't work with this because of deals that she has made, and that there is nothing she can do to save Clara. There's nothing the Doctor can do either. He threatens Ashildr, threatens to rain hell down upon what she has built up. Clara stops him mid-threat, telling him that he would stop the instant he heard a baby crying. She then tells the Doctor to not seek revenge, to get on with his life and to not stay alone, because he can't handle that (he really can't, which we have seen numerous times). She says good bye, and goes into the street to await death, while the Doctor watches from the doorway.
This is, of course, all the Doctor's fault. He gave Ashildr immortality then left her for 800 years, without a thought of the consequence to his actions. He forced Clara into situations that made her think like him. He runs in, fixes problems, and then doesn't stick around to deal with the fallout. If the Doctor had acted with more thought and care for the consequences, maybe Clara would still be alive.
But probably not since this was Jenna Coleman's last season anyways...
