Superlative adverbs are adverbs ending in -est. So think of big, bigger and biggest. Biggest is the superlative adverb due to the it ending in -est and having the 'superior' effect which is linked to its name of superlative.
The answer is Ethos
Thats what I think
The theme can be, a man is alone in the cold Yukon with nothing but a dog, and all odds are against him, including nature. A theme is an outline of the story by not getting into details