In Seasons 4–5, everything changes when y/n Byers—Will’s emotionally sensitive, intuitive sister—doesn’t just sense Vecna but becomes psychically touched by him, discovering she has powers that manifest through emotion rather than force: she can slip into minds, feel memories like physical spaces, and move through the Upside Down without losing herself, which is exactly why Vecna enters her mind deliberately, invading her thoughts with visions of the Creel House, his childhood, and his belief that humans are weak because they love, attempting to groom her into understanding him; unlike Will, who feels Vecna like a shadow pressing against his neck, y/n experiences him as a presence that speaks, argues, and tries to rewrite her fear into loyalty, forcing her to fight him inside her own mind while Joyce—desperate and relentless—refuses to believe her daughter is lost, Hopper risks everything to protect her, and Eleven, quiet but fierce, recognizes y/n’s powers as something different from her own and trains with her, teaching control while learning that y/n’s strength comes from connection rather than isolation; the Wheelers are deeply affected as Hawkins fractures, with Mike becoming more emotionally driven and protective than ever, holding the group together through sheer loyalty, Nancy growing colder and more determined as she researches Vecna’s history, Karen trying to shield her children from a town collapsing into fear, and little Holly Wheeler becoming a haunting symbol of what’s at stake when the Upside Down begins bleeding into homes, flickering lights above her bed reminding everyone that innocence is what Vecna ultimately wants to erase; Dustin keeps hope alive with humor and intelligence, refusing to let fear win, Lucas balances grief and courage as he protects Max, who survives Vecna’s curse but remains fragile and deeply bonded to y/n through shared trauma and recovery, while Steve stands as a steady, selfless protector, Robin sharp and perceptive, and Erica fearless and outspoken as the town descends into chaos; as Season 5 unfolds, Vecna attempts to fully claim y/n by trapping her consciousness inside the Upside Down, showing her a world without pain where she wouldn’t feel overwhelmed or afraid, but anchored by Will—who understands her better than anyone—and the memories of the people who love her, y/n turns her powers inward, using empathy as a weapon, flooding Vecna’s mind with everything he rejects—childhood comfort, loyalty, sacrifice, and love—causing his control to fracture, the Upside Down to destabilize, and the gates to collapse, leaving Hawkins scarred but alive, families broken and rebuilt, the Wheelers closer yet forever marked, Will finally free of the shadow that followed him for years, and y/n emerging not unscarred but whole, no longer the girl Vecna tried to claim, but the one who proved that feeling deeply was never a weakness—it was the thing that ended him.