Mouni Roy, in her interview with Film Companion, revealed that while shooting for her role as Junoon in Ayan Mukerji’s Brahmastra, the director and actor discovered a shared connection in that both are devotees of Lord Shiva. Roy said Mukerji would consistently remind her to hold on to that spiritual bond she feels. “Draw parallels to that, that’s who you are connected to and that’s how you will approach [the role]. That’s the kind of respect you talk with, that's the kind of respect you command,” Roy said, recalling the instructions Mukerji gave her.
Roy also recounted that Mukerji was emphatic about the film’s Indian roots. Although she is the antagonist in the film, the strength that Junoon embodies was inspired by Goddess Kali. The actor said she needed to unlearn a lot for this role and described Mukerji’s process as meditative. “He knows what he wants,” said Roy of Mukerji.
See more here: