Erin Bell

Erin Bell was the main protagonist and redeemed villainess from the 2018 film, Destroyer.

She was played by Nicole Kidman

Backstory
Erin Bell was a LAPD detective, and her backstory revealed that (at least) 16 years prior to the events of the film, she and her partner Chris were working undercover to take down notorious bank robber Silas Howe. The plan included Erin and Chris infiltrating Silas' gang, which had his girlfriend, Petra, as one of the members, and during their mission, Erin and Chris became romantically involved. As their relationship progressed, however, Erin became pregnant with Chris' child--a daughter later named Shelby--and with that, the plans changed. Instead of planning to take down Silas and his gang, Erin turned heel by informing Chris that they will become legit participants in the robbery, with her new plan consisting of taking their share from the robbery and running off together; while claiming to their superiors that they had lost contact with the gang.

The robbery went as planned, but after a dye pack exploded in Silas' face, Silas re-entered the bank and killed the teller who planted the pack. Chris re-entered and intervened, only to end up shot to death by Silas. As for Erin, she drove off with Toby (one of Silas' members), who held her at gunpoint until she crashed her van into a dumpster, seriously injuring Toby. Afterwards, the evil Erin took her share from the robbery and hid it in a storage unit, and returned to her job; all the while keeping her original plans and her heel turn a secret.

Events
In the years that passed entering the beginning of the film, Erin gave birth to Shelby and was in a relationship with a man named Ethan, while carrying anger and guilt over Chris' death. She was brought back to the case involving Silas when a John Doe was found murdered in the film's opening, after which Erin received a $100 bill with dye on it. After interviewing Toby and a lawyer named Dennis DiFranco (the latter of whom laundered the money from the robbery), Erin learned that Silas was planning another heist due to being out of funds, and it was later in the film that Erin engaged in a shootout with Petra and the other robbers. She later tracked Petra and abducted her, after which she ordered Petra to give more info on Silas.

The film's climax revealed Erin's past villainy, as she was shown at the storage unit obtaining her share from the robbery, only to find that it was mostly covered in dye. She took some of the unstained bills and paid Jay, Shelby's 23-year-old boyfriend, to move to Spokane and never see Shelby again, and she later met Shelby at a diner and spoke about the anger she carried (without revealing the entire truth) and voiced her love for her daughter. Erin later engaged in a confrontation with Silas, which ended with Erin shooting Silas to death. She later went to Antonio, her partner, and gave her a stained bill, confessing to her role in the robbery years prior and giving up Petra's location. Afterwards, Erin fatally succumbed to the internal injuries she suffered during her fight with Petra; dying peacefully as she sat in her car.