In the Marvel Cinematic Universe, the Red Skull’s ultimate punishment is to guard the Soul Stone on the planet of Vormir, never able to possess it or use it for himself. This eternal assignment is a fitting fate for the superhuman Nazi, and Uncanny Avengers reveals exactly why.
The Red Skull is one of Captain America’s oldest and strongest enemies. Johann Shmidt grew up as an orphan in Germany before the Second World War. Growing up as a troubled young child, he attached himself to Adolf Hitler and the Nazi cause and rose quickly in the ranks of the Third Reich. However, in the comics, the Red Skull is able to survive into the modern day like his nemesis Steve Rogers, repeatedly attempting to seize control of the world. Red Skull is one of Marvel's most despicable villains, being not just opportunistic or callous, but a true psychopath.
In 2012's Uncanny Avengers #2 - written by Rick Remender and drawn by John Cassaday - the Red Skull manages to steal Charles Xavier's psychic powers. Attacking New York, he seizes mental control over Thor and uses the Asgardian Avenger to terrorize innocents. It is revealed via narration that Shmidt is a psychopath in the clinical sense of the word. That means he is unable to feel love, but instead feels an intense sense of longing for domination. Red Skull longs to control and possess, showing why being set to guard a cosmic artifact he can never claim would be his ultimate torture.
The Red Skull is one of the most dangerous villains in the Marvel Universe, and his psychopathy goes a long way to explaining why. Captain America’s greatest foe experiences no empathy and desires nothing less than global domination. Even as a child, Shmidt was a killer, having no sense of other people except as potential belongings. While his routine humiliations and losses at Captain America's hands constantly enrage Red Skull, the ultimate punishment would be to be stripped of any ability to enforce his will on others, trapped within spitting distance of power he can never claim as his own.
Unlike other comic book villains which are often just called psychopaths, Red Skull fits the clinical definition, meaning that empathy is truly beyond him, and his conquests are the thing that means most to him in the world. In attacking New York and gaining mastery over Thor, Captain America's nemesis revealed the truth about his chilling motivations, and made the Red Skull's MCU fate even more fitting.