Since US Agent's appearance in The Falcon and the Winter Soldier, the looming possibility of the Dark Avengers appearing in the Marvel Cinematic Universe has become more evident. The Dark Avengers represent an antithesis version of the original team, made up of heroes and villains resembling established Avengers.
The MCU hasn't officially announced the debut of this team, but a now-deleted post from Wasp actress Evangeline Lilly teases a potential return of Ant-Man actor Corey Stoll as Darren Cross, aka Yellowjacket, in Ant-Man and the Wasp: Quantumania. Should this be accurate, Cross' reintroduction to the MCU could be a dangerous addition to the theorized team and spell disaster for the pint-sized heroes.
The last time Cross was seen, Scott Lang destroyed the technology that powered his shrinking abilities and suit, causing a malfunction that seemingly shrunk Cross into himself within the Quantum Realm. However, as Scott's return in Avengers: Endgame shows, this doesn't necessarily mean Cross is lost forever.
Following his return, Cross' vulnerability in a world that moved on without him, along with his abilities, could catch the eye of Valentina Allegra de Fontaine. Since she's already shown she preys on the powerful and mentally unstable by recruiting John Walker, it's no surprise that she would add Cross to her growing roster of morally ambiguous "heroes."
In Ant-Man and the Wasp, Scott's journey into the Quantum Realm gave Hank Pym and daughter, Hope Van Dyne, a way to find the long-lost Janet Van Dyne. Upon her return, she revealed the Quantum Realm gave her abilities that she used to heal the film's villain, Ghost. Like Janet, it's entirely possible that Cross' much shorter time in the Quantum Realm could still bestow powers upon him.
Without abilities introduced in the Quantum Realm, the strength given through the Pym Particles is already comparable to that of the Hulk's. Like the Hulk, Ant-Man was able to take out a Chitauri Leviathan in one punch, so the particles can make a user just as powerful as Bruce Banner's alter ego. Those abilities coupled with exposure to the Quantum Realm could give Cross access to a power he never knew was possible. However, his time in the Quantum Realm could also make his mind even more unhinged as a side effect.
Escaping the Quantum Realm and carrying its power could make him highly dangerous. Even worse is that Cross more than likely still carries some Pym Particles that could have been altered or enhanced while in the realm. The MCU has only teased the potential of the particles by growing and shrinking Scott past his limits. However, if Cross unlocks more abilities, that could place the film's heroes in greater danger. Plus, with his knowledge of the Quantum Realm, he could easily adapt his powers to the Pym Particles he took with him and demonstrate his dominion over molecules, the Quantum Realm and the multiverse itself.
Ant-Man and the Wasp: Quantumania looks to dive deeper into the Quantum Realm than ever before. That means that even more secrets could be uncovered, including the reintroduction of Cross. Should this be the beginning of something new for the character, he could be one of the most dangerous additions to the Dark Avengers yet. However, his power from the Quantum Realm and instability could even make him an even greater danger to the MCU as a whole.
Directed by Peyton Reed, Marvel Studios' Ant-Man and the Wasp: Quantumania stars Paul Rudd as Scott Lang/Ant-Man, Evangeline Lilly as Hope van Dyne/The Wasp, Michael Douglas as Hank Pym, Michelle Pfeiffer as Janet van Dyne, Kathryn Newton as Cassie Lang and Jonathan Majors as Kang the Conqueror. The film arrives in theaters Feb. 17, 2023.