New Delhi, Aug. 9 -- After months of secrecy surrounding Sadie Sink's mystery character, the Stranger Things actor has confirmed that she plays Jean Grey in Marvel Studios' Spider-Man: Brand New Day, marking the MCU debut of one of Marvel Comics' most important mutants.

Jean Grey is one of the founding members of the X-Men and one of Professor Charles Xavier's earliest students. In the comics, she is a powerful telepath and telekinetic whose abilities eventually become vastly more powerful after her connection with the Phoenix Force. Marvel describes her as one of its central mutant superheroes, having first appeared with the X-Men in Uncanny X-Men #1 in 1963.

Her history with Spider-Man, however, is considerably less extensive. Jean an...