Hellen Gravely is the owner of The Last Resort and the secondary antagonist in Luigi's Mansion 3. Her name is likely a reference to "Hell" and "graves." She owns a ghost cat named Polterkitty, and has a tendency to assume a haglike, disheveled form when upset, which she is greatly embarrassed about and suppresses using makeup.
Priot to the events of the game, Hellen tricked Professor E. Gadd into coming to her hotel and managed to release his collection of ghosts, leaving the professor to be captured inside a painting. She later invites Luigi, Mario, Princess Peach, and three Toads to her resort, with the intention of having them captured as well. When meeting Luigi’s vacation party, Hellen wears sunglasses and hides her semi-transparent aura in order to disguise her true nature as a ghost, similar to the other employees. She welcomes the group to her hotel and escorts them to their rooms on the fifth floor, planning to ambush them in the night so King Boo could trap them in portraits.
After Hellen successfully captures Mario, Peach, and the Toads, she returns to the fifth floor to bring Luigi to King Boo; she watches with admiration as King Boo tries to imprison Luigi in a painting, only for him to narrowly escape down a laundry chute leading to the basement, where he finds the Poltergust G-00. Throughout Luigi's adventure, Hellen watches his progress from the Main Observation Room on the fifteenth floor, growing increasingly frustrated with her staff's inability to capture Luigi. By the time Luigi defeats Captain Fishook in The Spectral Catch and rescues the third Toad, Hellen finds herself confronted by a disappointed King Boo; despite her efforts to placate him, she is quickly brushed off as King Boo takes one of the two remaining portraits to the hotel's roof without saying a word.
When Luigi reaches the Master Suite, Hellen confronts him over a large monitor, revealing that she has Mario's painting in her private office. While clearly upset with Luigi's progress, she comments that his presence here gives her the chance to personally defeat him and present him to King Boo, hopefully regaining his trust. She then continued monitoring Luigi from her office, leaving him to contend with her remaining ghost minions and her high-tech security measures as he sought the keys to open the path to her.
When Luigi finally reaches her, she angrily blames him for her losing everything, unintentionally exposing her true face in the process. After reapplying her makeup, she turns her office into an arena and battles Luigi personally. She is ultimately defeated and captured in the Poltergust G-00, sharing a capsule with Polterkitty. She is last seen during the credits, admiring a captured and frustrated King Boo from her own capsule.
And she is voiced by Susanne Blakeslee in the English dub and her Japanese voice is unknown.