Analyze how effective the ending of the story is, where only the outcome and not the details are known.

I think you have to consider that this is an escape story. This means that it is based on adventure and meant for escapism rather than any thoughtful consideration. The climax is the classic man vs man final fight scene. I think the fight serves its function resulting in the protagonist/ hero being the winner. That information is all that is needed for this genre of fiction.