WARNING: The following contains spoilers for Mary Jane & Black Cat: Beyond #1 by Jed MacKay, C.F. Villa, Erick Arciniega, and VC's Travis Lanham, now on sale from Marvel Comics
The Marvel Universe has long embraced morally questionable characters, infusing the typically straight-laced superhero genre with a touch of ambiguity. However, as characters evolve, it's rare for them to actually maintain that flexibility as they become more defined. Luckily, there's one Marvel anti-hero who still finds ways to truly tip-toe the line between a self-sacrificing hero and a ruthless antagonist.
Although she spends most of Mary Jane & Black Cat: Beyond working to save Spider-Man, Black Cat still uses the opportunity to effectively take out one of her villainous rivals. On top of being a good reminder of just how ruthless Black Cat can be, it serves as a good showcase for why she's Marvel's wild card in a way Catwoman isn't anymore for DC.
Mary Jane & Black Cat: Beyond #1 largely focuses on the titular pair being forced to work together to save Peter Parker. Cornered by the Hood while still unconscious in his hospital bed, the pair's best chance to rescue Spider-Man is to recover the villain's mystical hood. This leads the pair across New York City, pitting them against a number of villains while seeking out the demonically empowered costume. Eventually discovering the demonic bag that had consumed the hood, Black Cat makes an unexpected deal with the creature: handing it off to the Hood, the bag quickly consumes the villain as well in front of a triumphant Black Cat and a horrified Mary-Jane. Although there's always a chance the Hood could return, it's a genuinely brutal moment where Black Cat seems to casually kill off an Avengers-level villain.
It also speaks to the unique position Black Cat holds in the Marvel Universe. There are plenty of characters who try to straddle the moral line between hero and villain. It's a difficult route for a character to take, often ending up firmly in one camp or the other. Even with Marvel's chief competition at DC, characters who can truly fluctuate between the two without losing sight of their core characteristics are few and far between. But Black Cat is someone who actually successfully rides that line. Her flirty nature and self-interested goals allow her to always skirt into any situation and escape without losing any of the genuine charm or touches of nobility she just hides under the surface.
Over the years, Black Cat has garnered plenty of comparisons to DC's Catwoman. Both are criminal love interests to their respective enemies, with a habit of breaking bad even while nominally being heroic characters. But while Catwoman has firmly settled into a heroic figure in Gotham City and more or less an unofficial member of the Bat-Family, Black Cat has remained a singular wildcard. Her time as the "Queenpin" during Superior Spider-Man saw her fully embrace villainy in a way that didn't betray her previous heroic moments. But her general regression back to a more heroic role still sees her insult heroes and openly commit crimes if they benefit her.
Black Cat's casual murder of another villain is a good reminder of just how ruthless the character can be. Although she's fleshed out enough to have a genuine heart-to-heart with Mary-Jane afterward, there's no denying that Black Cat gets to have an edge that even the formerly full-time villainous Catwoman doesn't. Black Cat can work alongside Captain America while also enraging Nick Fury. There's a flexibility to the character that even her distinguished competition lacks now that Catwoman has openly addressed and embraced her feelings for the Dark Knight. Catwoman becoming a heroic figure is inspirational and engaging, but it means she lacks the cold agency that Black Cat gets to bring to the Marvel Universe.