The Red Skull was never able to get the Soul Stone in Avengers: Infinity War and Avengers: Endgame, and the reason why he was chosen and why he was never able to obtain it may come directly from the comics. The obvious explanation is that he couldn’t sacrifice something that he loved because he was isolated, but there may be more to the story than that.
Red Skull (Hugo Weaving) disappeared after interacting with the Space Stone at the end of Captain America: The First Avenger, and for years the mystery of his whereabouts went unresolved. In Avengers: Infinity War, he re-emerged on the planet Vormir – played by Ross Marquand – as the keeper of the Soul Stone. After meeting Gamora (Zoe Saldana) and Thanos (Josh Brolin), Red Skull laid out the rules for the Stone Stone and explained that in order to obtain it, one must give up what they love most. This forced Thanos to kill Gamora in Infinity War, and Black Widow (Scarlet Johansson) to give up her life in Endgame.
For years, Red Skull was trapped on Vormir, unable to obtain one of the six Infinity Stones, even though it was there for the taking. In Infinity War, Red Skull explains that he guides others to a treasure he can never possess. It’s understood that the Red Skull can’t give up what he loves because he’s trapped on a deserted planet, but the explanation for why he can never have the Soul Stone may go deeper than that. In Marvel Comics, the Red Skull is simply incapable of love.
In Captain America #298, it was revealed that as a 30-year-old drifter in Germany, Red Skull thought he had fallen in love with a woman, but after she spurned his affections, he attacked her out of rage. Years later, he realized that what he really felt was just lust. The Red Skull has never loved anyone, including his own daughter, Sin. Red Skull’s loveless relationship with his daughter is part of what caused her to grow up as a hateful, vindictive woman desperate to earn her father’s approval. As Red Skull has explained multiple times, the only thing that’s ever mattered to him is his hatred of Steve Rogers. Love has never entered his thoughts.
The MCU never had a chance to explore this facet of the character, but given that Captain America: The First Avenger seemed to feature a mostly comic book accurate depiction of the Red Skull, it does seem possible that he, like his comic book counterpart, has no capacity for love. This means that there was no way that Red Skull could ever obtain the Soul Stone, even if he did find a way to lure someone to Vormir. Given Red Skull’s comic book history, it seems perfectly fitting – and perhaps even poetic – that the Soul Stone, an object that requires someone to give up what they love, is watched over by someone whose own inability to love makes them incapable of ever obtaining it.
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