129
A ruthless decapitation
(lemmy.world)
Smite is aimed at the bag of holding. Not at the boss itself.
Going by the rules. When a bag of holding is destroyed. The contents contained within are scattered to the Astral Plane.
Yeah. This was quite amusing on Dungeons & Daddies but I wouldn't allow it either. Essentially 1 Sleight of Hand or Athletics roll plus an attack roll with advantage (blind) shouldn't equal an instant kill even if it destroys a magic item.
I would argue that the contents get drawn in, but since he is not even half in there he would just take a lot of force damage and the bag gets destroyed. (and maybe the boss is bald afterwards and lost their hat)