Zee befriends lonely, unpopular girl Casey Krinsky. Zee's new friend gets a little too attached, and then turns out to have the ability to steal superpowers...
Tropes:
- Accidental Misnaming: Almost everyone gets Casey's name wrong.
- All Your Powers Combined: Casey turns into an amalgam of all the Super Hero Girls after absorbing their powers.
- Break Them by Talking: How Zee defeats Casey in the Hall of Mirrors.Casey: Smoke and mirrors, Princess of Prestidigitation? I expected better from you. Come out here and fight! I'm sick of seeing my pathetic little face! I mean your face! I mean… (screams in frustration)
Zee: What's the matter, Casey? Don't like what you see?
Casey: No! Nobody does!
Zee: You're wrong! I liked you! At first. So did my friends! It was the evil plot to change who you are that mucked it all up.
Casey: Stop it! Quit it!
Zee: You could have had the friendship and acceptance you wanted, if you had only accepted yourself. - Cassandra Truth: At the end of the episode Casey tries to tell everyone at school the Super Hero Girls' secret identities. Nobody believes her, because of how crazy Zee (who'd been turned into Casey at the time) was talking the day before.
- Eyes Are Mental: When Casey shapeshifts into Zee, her eyes remain green, and Zee's stay purple even after she’s mode-locked to look like Casey.
- Hall of Mirrors: Casey chases Zee into the amusement park's hall of mirrors, where she's confronted with the reflection of her real self, as Zee gives her a "The Reason You Suck" Speech.
- I Just Want to Be Special: Casey's motivations for latching onto the beautiful, popular Zee.
- Instant Expert: After absorbing all the Girls' powers, Casey manages to use all their powers with ease.
- Motive Rant: Casey goes into one when Zee asks her to let go of her.Casey: [to Zee] You have everything a girl could ever wish for! Popularity, beauty, friends! And I'll never let go until...(takes the form of Zee) I have it too!
- Nice Job Fixing It, Villain: If Casey hadn't (accidentally) used Zee's powers to make Zee look like her, everyone at school might have actually believed her when she tried to reveal the Super Hero Girls' secret identities at the end.
- Power Parasite: Casey has the power to take on not only the appearance of others, but also take whatever superpowers they have, leaving her victims powerless.
- Rage Against the Reflection: Along with smashing the mirrors while trying to get Zee, Casey is lashing out in self-loathing towards herself.
- Redemption Rejection: After Casey loses her stolen powers, Zee offers her a chance to start fresh. Casey angrily refuses.
- Running Gag: See Accidental Misnaming.
- Voices Are Not Mental: Casey is played by Kari Wahlgren when she takes Zee's form, and Zee is played by Lara Jill Miller when she's mode-locked to look like Casey.
- Voice of the Legion: Along with having her appearance look like a combination of the Girls, she also has a combination of their voices after she takes all the Girls' powers.
- Yandere: Casey, although she ends up wanting to destroy the girls to take their place, especially Zee.
