Doctor Who: 9 Ways To Kill The Doctor Permanently

If you chose to kill a Time Lord in this way, it'd take you a good long while, but let's say that you're feeling particularly bloodthirsty, and you want to make your victim suffer.

Something that's been mentioned many times throughout the show's history is that Time Lords can only regenerate a finite number of times - usually a dozen. So if you wanted to, you could murder one of them repeatedly, burning through every single one of their regenerations until no more remain, forcing them to die for good.

Rassilon threatens the Doctor with a death like this in Hell Bent, saying that he's "got all night" to slaughter his way through each of the Doctor's remaining bodies. Even before this, the Eleventh Doctor actually did run out of regenerations and had resigned himself to death, only to be granted a fresh cycle by the Time Lords.

Now, The Timeless Children's alteration of Time Lord history did complicate this topic somewhat, as it's now unclear if the Doctor can regenerate infinitely, or if they still have that aforementioned limit. But for the sake of this entry, let's just assume that it's still possible for the Doctor to run dry in the regenerations department.