Nell — Acceptance
Is anything sadder than Nell's story in this show? I mean, seriously — I'm still devastated by the episode that reveals her ghostly alter-ego. In fact, it's in that same episode that we discover why Nell most embodies the stage of "acceptance" — after her husband, Arthur, dies following a run-in with the Bent Neck Lady, Nell loses her grip on reality. Her visions of the terrifying ghost become a near-constant, as do her night terrors.
By the time a full year has passed following Arthur's death, Nell has pretty much accepted that her fate will eternally be bound with Hill House. She doesn't seem scared or surprised when she sees Olivia's ghost upon returning to the cursed estate; actually she's elated, and embraces her dead mother. When her siblings later arrive at Hill House to investigate, she utters a heartbreaking, but resigned statement about her life to convince her brothers and sisters they need to move on: "I loved you completely, and you loved me the same. That's all. The rest is confetti."