Captain Marvel: 9 MCU Loose Ends It Answers

Many of the Phase One superheroes were created from serums or through access to vibranium. But others had their legacies forged by their interaction with the Tesseract. The Tesseract was also the marker of whether a soul was worthy or not. The Red Skull was most certainly not worthy, which meant he was shot into oblivion, whereas Loki was an ongoing case of moral limbo, which meant that the Tesseract acted as both his salvation and his undoing.

As discovered in Captain Marvel, Carol Danvers' fate is also tightly woven with the Tesseract. Carol's Kree mentor, Dr Wendy Lawson, aka Mar-Vell, used it to power the engine of her SHIELD-sanctioned ship, which Danvers was then forced to destroy and thus inadvertently take an irreversible hit of Tesseract/Infinity Stone energy.

When we remember that the Tesseract came into SHIELD's possession after Howard Stark had it extracted from the bottom of the ocean following Captain America's plane crash, the connection is pretty mind-blowing. You could almost consider Captain Marvel as a super-powered half-cousin to Tony Stark, Steve Rogers and even Thor.