The Infinity Stones are ancient power sources that were brilliantly woven into most of the MCU's first three phases of films. The Tesseract, AKA the Space Stone, debuted in Avengers: Infinity War. After he wiped out half of all life in the universe, Thanos used the Infinity Gauntlet to destroy the Stones. This necessitated the Avengers' using the Quantum Realm to heist the Infinity Stones in the past so they could assemble their own Infinity Gauntlet, undo Thanos' genocide, and kill the Mad Titan.

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The first known human to receive superpowers from an Infinity Stone was Carol Danvers (Brie Larson) in Avengers: Age of Ultron.

Though WandaVision was ultimately about Wanda Maximoff discovering she has power over chaos magic as the Scarlet Witch, the series heavily emphasized the continuing importance of the Mind Stone. The incarnation of Vision that Wanda built to be her husband using the part of the Mind Stone still within her gained greater self-awareness, and he used the Mind Stone's abilities to unlock the memories of the people of Westview, who were held in psychic captivity by Wanda. Vision also used the Mind Stone's power to unlock the memories of White Vision, restoring him.

Meanwhile, WandaVision served as the superhero origin story of Monica Rambeau. By repeatedly ing through Wanda's magical Hex barrier, Monica's DNA was rewritten and she gained superpowers. While it's not clear how much of the Hex was powered by Wanda's Mind Stone-derived abilities and how much came from her chaos magic, Monica can also be considered to be powered by an Infinity Stone. Obviously, the Mind Stone had the greatest overall impact on the MCU when it comes to how many superheroes were created by it.

Although the Infinity Stones are gone (barring more time travel to retrieve them), they have left an irreversible mark on the MCU and its characters. Whether it's through Captain Marvel or the cast of WandaVision, the Infinity Stones continue to determine the future of the MCU and its heroes since Doctor Strange in the Multiverse of Madness. Beyond how powerful the Infinity Stones were, it also speaks to how huge their story in MCU Phases 1-3 was and how masterfully Marvel Studios' filmmakers integrated the Infinity Stones into their characters' adventures, both in the past and still to come.

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