Behind the Waterfall is a room. "Though one wall of the cave is open to the waterfall, the quantity of water is so great that barely any light comes through from the outside." Behind the Waterfall is dark.
Brightness is a kind of value. The brightnesses are guttering, weak, radiant and blazing. The torch has a brightness. The torch is blazing. The torch is lit.
Understand "blow out [something]" or "blow [something]" or "extinguish [something]" as blowing out. Blowing out is an action applying to one thing.
now brightness of torch is the brightness before the brightness of the torch;
say "The light of the torch dies to [brightness of torch]."
Instead of blowing out the guttering torch:
say "Fool! Do you want to put it out entirely?"
Rule for writing a paragraph about a shiny thing:
say "The [brightness of the torch] light of [the torch] reflects in the surface[if the number of shiny things in the location > 1]s[end if] of [the list of shiny things in the location]."