Toxicator

Plot
Marinette is asleep, until she gets a call from Alya, Alya tells Marinette about the British exchange student who is coming to their school today, to which Marinette is excited about. Marinette gets ready and heads off to school, along with Adrien, Ben, Alya, Chloé, Sabrina, Nino, Kim, Juleka, Rose, Alix, Nathaniel, Ivan and Mylène.

Class has begun, while Ben asks about the exchange student's whereabouts, to which they walk in through the door and introduces herself as Alicia Greauxpois. Chloé stands up and looks at her, while Miss Bustier tells her to sit down. Miss Bustier looks at Alicia and tells her to sit beside Marinette and Alya. Alicia walks to their table and sits down on the seat she was meant to be sat on. Miss Bustier then begins writing on the board.

Alicia leans over towards Marinette and talks about Adrien, and how she is in love, Marinette replies about the same thing, until they started talking about Adrien together, until Chloé tells Alicia that Adrien will never love her because she used to stutter every time she was near Adrien, to Alicia's embarrassment. Alicia gets up from her seat and runs away.

Hawk Moth's lair opens the windows to reveal Hawk Moth's presence. Hawk Moth reaches his hand, waiting for the akuma to land on his hand. He covers the akuma and releases it, hoping he would akumatize Alicia.

Alicia storms off about Chloé embarrassing her, suddenly, the akuma flies onto her arm pads, possessing it. Hawk Moth tells Alicia to get Ladybug and Cat Noir's miraculouses, to which she agrees, thus, transforming into Toxicator, a villain who has the ability to escort different gases as various attacks or defences.

Toxicator barges through the doors and sees Marinette. Ben looks at Toxicator and transforms into Bloxx and charges at her, she blasts him towards a brick wall. Kim runs towards him and asks if he's okay. Bloxx nods. Marinette runs away before Toxicator attempts to get her, she runs towards her, but gets thrown onto the roof by Bloxx. Marinette, Adrien and Alya transform into Ladybug, Cat Noir and Rena Rouge. Nino walks towards Rena Rouge, weak as he doesn't have the turtle.

Characters

 * Marinette Dupain-Cheng/Ladybug
 * Adrien Agreste/Cat Noir
 * Ben Tennyson
 * Alya Césaire/Rena Rouge
 * Nino Lahiffe
 * Chloé Bourgeois
 * Sabrina Raincomprix
 * Lê Chiến Kim (first appearance)
 * Juleka Couffaine (first appearance)
 * Rose Lavillant (first appearance)
 * Ivan Bruel (first appearance)
 * Mylène Haprèle (first appearance)
 * Max Kanté (first appearance)
 * Alix Kubdel (first appearance)
 * Nathaniel Kurtzberg (first appearance)
 * Alicia Greauxpois (first appearance)
 * Miss Bustier

Villains

 * Gabriel Agreste/Hawk Moth
 * Toxicator (first appearance; only akumatized)