Spider-Man: Brand New Day may have just confirmed the biggest Sadie Sink theory

Steve Lacy spoiled Sadie Sink's long-debated Spider-Man: Brand New Day role at the movie's red carpet premiere. If he is right, then it would mean that the rumors of the Stranger Things actress playing a fan-favorite Marvel character in the movie are true. Lacy gave away the biggest spoiler from the upcoming Spider-Man movie just days before its release.

As for the reason behind her character's possible antagonism throughout most of the movie, rumors suggest that she is merely a puppet in Spider-Man: Brand New Day. Moreover, Deadline also reported last November that Sink is appearing in Avengers: Secret Wars.

It means that based on Steve Lacy's recent confirmation of Sadie Sink's role and her involvement in Secret Wars, she is in the MCU for a while.

Sadie Sink plays Jean Grey/Marvel Girl in Spider-Man: Brand New Day:

Songwriter and singer Steve Lacy attended the Los Angeles premiere of Brand New Day this Monday. At the red carpet, a reporter asked Lacy about his favorite character in the movie. The singer responded that his favorite character in the movie was Jean and even spoiled that she is the villain of the movie. He also said that there is a reason behind Jean's villainous turn in Spider-Man: Brand New Day but did not specify any further.

With these revelations, we now know what to expect from the next Spidey flick. It seems that Sadie Sink's Jean Grey will begin her MCU journey as a minor antagonist for the wall-crawler instead of starting as a hero like her Marvel Comics counterpart. But a recent leak suggested that Jean's villainous start in the MCU is not out of her own volition.

Leaks suggest that Jean has a sister in Brand New Day:

An Internet scooper revealed that actress Olivia Booth-Ford is playing Jean's sister, Sara, as she is named in the comics. Sara is a human in the comics, and the same applies to the MCU as well. However, it seems that Sara is kidnapped, and her captors force Jean to work for them, making the psychic mutant cross paths with Spider-Man.

If this rumor is true, it means the Department of Damage Control (DODC), not Jean Grey, is the real villain of Brand New Day. Therefore, the entire movie could be about Peter Parker finally realizing the DODC's nefarious plans and turning on the government team after collaborating with them in the first half of the movie.

We did see Spider-Man fight some DODC agents in a recent trailer. These fight sequences could occur in the third act of the movie, as the wall-crawler discovers the DODC's deception. But it should be noted that these are just rumors, and we will learn more this weekend as Spider-Man: Brand New Day releases in theaters. The official logline of the movie reads:

"It's a BRAND NEW DAY for Peter Parker. Fighting crime full-time as Spider-Man in a world that doesn’t remember him—and the pressure of seeing his old friends move on without him—sparks a change in Peter he may not have the power to control. But that transformation might also be the only thing that can stop a shocking new threat to the city and those he loves - a powerful villain no one can even see."