10. Jenny Kills Him
For this theory were going say Jenny had the capability to regenerate. Hey, remember when I wrote an article about
how awesome Jenny is? Forget all that for the next minute as you read this. Were going to imagine what happened if Jenny was the reason for the next regeneration. Parallel to Amy, people who wait for a certain person end up resentful. We dont know what Jenny did after she flew away to the stars, but we can guess she went looking for The Doctor. We know she never found him, and that could cause her to be resentful. The Doctor takes Clara some place safe, preferably on Earth, in America, in the countryside, and this girl comes up to him. And hes his normal self, and she says So you really are the Doctor? and he confirms and she pulls a gun, and says
Hello Dad. Enter a monologue about how she looked for him and she tried to change but in the end she realized being the way she was made to be was easier and pulls the gun on him. He spends the episode trying to talk her down, finally mentions something about barely recognizing her and she pulls the gun. At this point, she'd probably say 'Goodbye, Dad.' And bam. She kills him twice, thinking shes killed him, but she killed him too close together and it doesnt effect the regeneration. At this point Clara pulls the gun from her and we have an epic strong female moment. The Doctor begs Clara not to kill Jenny, but tells Jenny to leave. And then Clara says something about You would have a daughter who kills you. This would give us the capability of having Jenny return, but in the last way we'd expect. And it could also give her a story arc. So yay! Jenny! This reason gets a 0/10 for possibility because I doubt Moffat would bring in a new character to kill the Doctor in one episode. But I love Jenny so of course she got a point.