Final Destination 5

[Thrifty]

there will be a "Saw vs The Final Destination" movie in our future where death tries to kill the saw master.

Weirdest slash fiction ever. 

I stopped watching the Saw films after II, but from what I understand, didn't Jigsaw manage to survive countless attempts to murder him?  He's already beaten everyone in the Final Destination series if that's true, and he doesn't even have superpowers.

No.  Jigsaw was definitively and unmistakably killed at the end of Saw 3.  Except the series uses a lot of tricks to keep him in the series.  There's his apprentices.  There's the devices he built before his death which weren't put into use until after.  There's a LOT of flashbacks and retconning.  He manages to convince an awful lot of his surviving victims to become his apprentices, which isn't the most implausible part.  The most implausible part is that it's said that he makes these machines because he's a brilliant civil engineer.  Yet somehow it's no big deal to train a strung out junkie and a dirty cop to do build the same thing.