Reese and her sister Audrey were the next two children Sully attempted to guide after his fallout with Sam. While playing tag with Audrey, Sully was chased into the street, where a car proceeded to hit and kill Audrey. After Audrey's death, Sully stopped interacting with Reese, which caused Reese to resent him, leading years of therapy. When Reese got older, she became obsessed with folklore and while studying abroad in Romania she learns that Sully is a zanna. She then sought out a witch, who sold her a spell that would allow her to see the zanna, as well as a knife capable of killing them -- despite the witch's protests that the zanna were good.
Sparkle believing Maddie had returned from dinner, jumps to his feet to greet her only to be greeted by Reese, who proceeded to drive in a knife into Sparkle's abdomen, repeatedly stabbing him and splattering glittery blood everywhere. The next day, after playing in the pool with her child, Zoe, Nicky Mermaid starts to relax in the pool. Nicky's moment of relaxation doesn't last long as Reese quietly sneaks up on the mermaid and brutally stabs her in the pool, leaving a literal bloodbath.
As Weems is hanging up the newly cleaned bed sheets of his child Fletcher's, he becomes suspicious that there is something watching him and attempts to look for it. When he finds nothing, he shrugs it off and goes back to the laundry when suddenly he is stabbed through the bed sheet with a knife. However, the stab was not fatal and Weems was able to catch a glimpse of his attacker fleeing. Weems later relates to Sam and Dean that "some chick" he never saw before stabbed him and drove off in a VW Bug, sending Dean on the search for Reese.
Dean is able to track down the VW Bug, but is promptly knocked unconscious by Reese and tied up in a barn. Reese takes Dean's phone and sends a text to Sam giving him their location. When Sam and Sully arrive to the barn, Sully is shocked to see it is Reese who has been killing the zanna. She accuses Sully of killing her sister, Audrey, and then abandoning her when she needed him the most. Sully tells Reese that Audrey's death was an accident, but that he still blames himself. When Reese threatens to kill Sam out of revenge, Sully offers himself up instead, telling her if she needs to kill him in order to feel better, he is okay with it, as it's his job to do what's best for the kid. As Dean frees himself, he tells Reese that revenge won't help her, and that while Sully made a mistake, there is nothing monstrous about him. With the knife pointed at his chest, Sully tells Reese he is sorry, causing Reese to sob and drop her knife. The two hug, with Sully reiterating his sorrow to her.