Both The Last Days of FOXHOUND and The Cobra Days interpret The Sorrow's ability to make a person "experience the sorrow of those they have killed" as this. Whereas in the game it's fairly straightforward (Snake is confronted with the ghosts of everyone he's killed in the game so far, who shout accusations at him, and he has to struggle past them) the former shows The Sorrow as dragging a person's mind to the other side and letting their victims have their way with them, and the latter shows it as him gripping a person and forcing them to experience the dying feelings of everybody they have killed at once.
- The Sorrow in The Last Days of FOXHOUND only did the former on Mantis, however: Liquid and Octopus were tested in the same way as Snake. Of course, he does run into the snag that the three people he tries it on are a Sociopathic Hero, a Blood Knight with Laser-Guided Amnesia and a Technical Pacifist: Mantis quickly realizes that all the people he's killed is ultimately water under the bridge, Liquid can't remember any of it and just takes all the carnage as a sign of how badass he is, and Octopus' test is completely empty because he's never killed a person in his life.'
Sorrow: This test clearly does not work anymore.