Avengers: Endgame - Everything That Changes If The Heroes Steal The Infinity Stones From The Past

9. No Twins, No Hawkeye, No Ragnarok

Even if there's a Battle Of New York, but the Avengers take the Tesseract and the Mind Stone (in the Sceptre) from Loki, that effectively wipes the Maximoff twins out of all future MCU movies. If the Sceptre doesn't fall into HYDRA's hands through their infiltration of SHIELD, then there can be no secret experiments carried out by Baron Von Strucker and no guinea pigs (successful or otherwise).

Sure, the twins might have become more conventional low-level villains working for someone else in their attempt to get revenge on Tony Stark for his company's part in their parents' deaths, but they wouldn't have become Scarlet Witch and Quicksilver. And that's a fairly huge change: without Quicksilver, Hawkeye would be dead for instance, and without Scarlet Witch, Tony would never have had the image of Earth's end that led to him building Ultron and Bruce Banner would not have lost control again, leading to his self-imposed exile.

That also means some of the major events of Thor: Ragnarok could ever have happened. Hulk wouldn't have been on Sakaar, for example, making Thor's escape from the planet in the Avengers Quinjet impossible. It's really quite hard to over-state how intertwined the Stones are in every storyline.

On top of that, of course, you wouldn't have Scarlet Witch's role in Civil War, which means no accidental mass murder and another trigger for the Sokovia Accords wiped out.

In the end, the HYDRA experiments that uncovered (and amplified) the Twins' latent superpowers might also end up being the key to the MCU's introduction of mutantkind (at least in a very vague sort of way), so it would be unlikely they'd wipe them out.