Content warning: contains discussion of incest
While relationships naturally form in teams like the Avengers, few bonds have been as strong as the one between siblings Scarlet Witch and Quicksilver. Ever since their debut, the two have been inseparable, following each other across teams and across the lines of good and evil. Though Quicksilver was sometimes controlling of Wanda's love life, their relationship in the main Marvel universe is often one of the purest examples of familial love, however, the same can't be said for their Ultimate counterparts.
First premiering in Ultimate Spider-Man #1 the Ultimate universe started as an attempt to modernize Marvel continuity and tell contemporary stories that couldn't be told in the main Marvel Universe. Creators Brian Michael Bendis, Bill Jemas, and Mark Bagley envisioned it as a jumping-on point for readers too intimidated by the main universe's decades of continuity. Instead of the Avengers, this universe had the Ultimates, and eventually, Scarlet Witch and Quicksilver joined their ranks. There were a few references to their relationship being close early on, but nothing too inappropriate. Unfortunately, all that changed with the release of Ultimates 3.
Coming from writer Jeph Loeb and artist Joe Madureira, Ultimates 3 reveals that Scarlet Witch and Quicksilver are far closer than anyone would have guessed. The first confirmation comes around Christmas time, when Captain America approaches the siblings to ask Wanda if she could wear a more modest costume. Quicksilver instantly takes offense to this and goes as far as threatening Steve. Cap is confused by the encounter, but Wasp tells him that it's because he loves her, and not in the way that siblings are supposed to love each other. Not long after Wasp drops this revelation though, Scarlet Witch is killed by an assassin. As if all of that wasn't traumatizing enough, the next issue starts with Wolverine recounting his time with Scarlet Witch and Quicksilver in their birthplace, Wundagore. Hating his son, Magneto tasks Wolverine with killing Quicksilver. He attempts to do so but is fought back by Wanda. While tracking the siblings, he catches a moment that is heavily implied to be more than intimate.
Readers later learn that it was Ultron who killed Wanda with a bullet designed to track her specific DNA. Quicksilver would go on to become obsessed with his dead sister/lover, even going as far as hallucinating her. While all of that sounds gross on its surface, the details of the actual comic make it much worse. Upon discovering Wanda's death, Wolverine says he needs to investigate it because "she could've been mine." He goes on to describe sleeping with Wanda's mother, and how much Wanda reminded him of her. Instead of letting the tragedy of a young woman's death speak for itself, Ultimates 3 centers the feelings of all the men who lusted after Wanda.
The decision to have Pietro and Wanda be in an incestuous relationship is a symptom of this larger problem. The grief of a brother who lost his sister is outweighed by the grief of a man who lost his lover. In an industry that is no stranger to failing its female characters, this storyline with Scarlet Witch and Quicksilver stands out as one of the most poorly thought-out moments ever published by Marvel.