Yeah, the show itself is inconsistent enough that I think at some point "don't think about it, just go with it" is the only option. *g*
There is definitely a certain amount of regeneration that takes place when they come back to life. They can't regrow limbs, as in Xavier's case, but they can clearly heal whatever killed them (we've seen them actually do that on many occasions), so as in, say, the case of the Immortal starving on the island, I'd assume that he came back to life fully un-starved, and then had to starve all over again. (Augh.) But then there are the times when their regeneration is clearly incomplete ...
That's a plausible theory, actually, that they can't come back if they'd just die again instantly! And I can't think of anything in the show to contradict it necessarily. (Come to think of it, I wrote something similar in one fic in which some Immortals froze to death and then didn't regenerate until they were thawed ...) so, yeah, this explanation works fine for me! :D
Torchwood had a similar instance of an immortal character lacking the PTSD you'd expect after being forced to come back to life and die multiple times under horrific circumstances -- in that case he was buried alive and canonically did revive and die in cycles of a few minutes for the entire time he was buried. And had no real trauma to show for it afterwards. Oh well.
Re: Reanimation
There is definitely a certain amount of regeneration that takes place when they come back to life. They can't regrow limbs, as in Xavier's case, but they can clearly heal whatever killed them (we've seen them actually do that on many occasions), so as in, say, the case of the Immortal starving on the island, I'd assume that he came back to life fully un-starved, and then had to starve all over again. (Augh.) But then there are the times when their regeneration is clearly incomplete ...
That's a plausible theory, actually, that they can't come back if they'd just die again instantly! And I can't think of anything in the show to contradict it necessarily. (Come to think of it, I wrote something similar in one fic in which some Immortals froze to death and then didn't regenerate until they were thawed ...) so, yeah, this explanation works fine for me! :D
Torchwood had a similar instance of an immortal character lacking the PTSD you'd expect after being forced to come back to life and die multiple times under horrific circumstances -- in that case he was buried alive and canonically did revive and die in cycles of a few minutes for the entire time he was buried. And had no real trauma to show for it afterwards. Oh well.