See, I think some are missing the point. My point is not that any one theory I have come up with (or others) is THE explanation for things that aren’t explained, but that there are possible explanations and Star Wars has a habit of not clearly explaining every turn and point in favor of the drama of the moment. From just the canon sources (regarding Maul and the Grand Inquisitor), there appears to be some dark force power that they can tap into to remain alive after otherwise deadly injuries. We have several characters run through with a lightsaber (or cut in half) and only Qui-gon dies. No explanation. But in each of those instances, what we see works to forward the drama. Lucas is the one who insisted that Filoni bring back Maul. He was cut in half, that is far worse than being run through. Though you could argue that the saber didn’t touch any part for very long and didn’t do as much damage. But Qui-gon was run through almost as fast and died. The Grand Inquisitor and Reva are run through slowly and both survive. Why? How? The force is the most likely reason. Do we really need all the details? No. Star Wars isn’t big on such expositions. Especially the PT. And this series is very tied to the PT.