...I'm confused a bit by Frankenstein's creations. Was the original monster (from the book and the original films) considered immortal? I never got that, so is this something new?
I haven't seen the most recent episode yet, so keep that in mind.
It's been a long time since I've read the novel, but as best I can remember there were no definitive statements that Frankenstein's creation was immortal. Tough and impervious to almost everything, and I think
it believed it was immortal, but I think that was left to the readers' interpretation. As for the original movies, in
Son of Frankenstein the "monster" had lapsed into a coma after having been struck by lightning, so that implies it can be killed if enough physical trauma is inflicted upon it. But considering the number of times the "monster" died at the end of one movie and was resurrected for the next, who knows?
But we all know how this stuff works. Any given creature--werewolves, vampires, zombies, etc.--have whatever capabilities the storyteller wants them to have. Someone could produce another Frankenstein movie and state the Creature is definitely immortal, and another could produce one five years later and obliterate the Creature by vaporizing it with a nuclear warhead. As long as there's a buck to be made, Frankenstein's creation will live.