Ep 21. Gamer

Marinette and Adrien's school is hosting a video game tournament called Gaming Week for all the students to participate in. Adrien is looking forward to competing as he is a skilled gamer, but Marinette is hesitant to join since she is less experienced. However, both of them end up signing up for the tournament with their alias usernames: Ladybug and Chat Noir.

Meanwhile, the villain Hawk Moth senses an opportunity to acquire more powers and sends his akuma, a small black butterfly that possesses people, to inhabit the body of Max, a gamer who is highly competitive but never wins any tournaments. This transforms Max into the supervillain Gamer, whose mission is to steal Ladybug and Chat Noir's powers by challenging them to beat him in a video game.

As the tournament progresses, Marinette and Adrien make it to the finals, where they are set to face off against Gamer. However, Max's obsession with winning leads him to cheat by using his akumatized powers to control the video game characters, causing chaos and destruction in the process.

Ladybug and Chat Noir realize that they must work together to defeat the villain and save the city. Marinette uses her wit and cunning strategy, while Adrien uses his gaming skills to try and outsmart Gamer. With time running out, the two superheroes must win the game before it's too late.

Throughout the episode, Marinette and Adrien also struggle with their identities as Ladybug and Chat Noir and the feelings they have for each other in their normal lives. Marinette is jealous of Adrien's attachment to his online teammate, while Adrien is beginning to suspect that Marinette might be Ladybug.

In the end, Ladybug and Chat Noir are able to defeat Gamer and restore peace to the city. However, they remain clueless about each other's true identities. As the episode closes, they both continue to wonder who could be under the masks of their superhero alter-egos.