Originally Posted by Fat R Inanimate
It's meant as the user will faint regardless of Sturdy or Focus Sash, much like using Selfdestruct/Explosion. If the opponent has Sturdy or Focus Sash, they will survive with 1 HP if they would be OHKO'd by Final Gambit.
Yeah well I know that now lol. Guess it WAS too good to be true! Oh well, that just ends up being something else to look out for before I attack.