Rise of Fawful is the 4th episode of A day with Bowser Jr.
Plot
Part 1 (The anniversary)
In Neo Bowser City, Bowser is shown to be giving a speech to his loyal subjects, for today is the fifteenth anniversary of the defeat of Fawful, the Mushroom Kingdom's most dangerous enemy, but Bowser Jr. humiliates himself during the speech when he receives a text which is heard by everyone due to not putting his phone on vibrate, but he is delighted to find out that the text is from Kylie Koopa. As Bowser continues his speech, Kamek is shown to be delivering breakfast to Ludwig who has been grounded for thirty-three days after the events of the previous episode, but he feels as if his punishment is unjust. Afterwards, Junior is shown to be talking to Kylie with KoopaChat, but he notices that her voice sounds different than what it is on television, but Kylie is able to make him forget about that by saying that she wants to interview him tonight at the airship personally and privately, but as she's talking about it the screen breaks up for a second, revealing her to be Fawful in disguise, but Junior does not notice this. Fawful says he requires Junior's code to enter the airship, and Junior thinks that "Kylie" must secretly be in love with him, so he tells "her" his code and where to find the airship in Water Land. Fawful's ship is detected by the soldiers in the airship's control room, so Hammer Bro. contacts Bowser for help. The ship avoids the Bullet Bills aimed at it, and once Fawful uses Junior's code to enter the airship he invades the control room and zaps Bowser with his new weapon known as the Rejuvenation Beam, and the commotion is heard by Junior while he's preparing for his interview, so he goes to investigate and witnesses Fawful kidnapping Ludwig before he reveals himself to Junior. Once Fawful explains everything, Junior realizes he wasn't talking to the real Kylie, and after Fawful is finished mocking him with his romantic feelings for her he jumps onto Junior's shoulder and takes a selfie of both of them, for he plans to show this picture to the Koopa Kingdom to make it seem like Junior was working with him, and when Junior tries to stop him from escaping he is knocked unconscious by Fawful's minion Midbus. Junior awakens in his room the next morning where he is met by Kamek who explains that the entire Koopa Kingdom now hates him for what has happened. After he explains to him how Fawful attacked the kingdoms all those years ago, he shows him an infant Bowser who has been turned into a baby as a result of Fawful's weapon, and the only way to undo this is to feed him the Age Mushroom, an almost extinct mushroom of which Fawful holds the last remaining samples. Junior is left feeling guilty over what he has done, but Kamek tells him that although anybody can fall, some people can rise up again.
Part 2 (The alliance)
Ludwig awakens in a circular bedroom where he is met by Fawful and Midbus, and he threatens to give them a beating if they don't tell him why he's here in the next thirty seconds, so Fawful sends Midbus away so he can discuss matters with Ludwig in private, saying it is for the greater cause. Fawful explains that his goal is to conquer the Beanbean Kingdom and all of the other kingdoms by forming an alliance with the Koopa Kingdom, but Ludwig is not convinced, knowing Bowser would never accept, but his perception changes when Fawful explains how he turned Bowser into a baby and claims that the reason is so that Ludwig can seize the throne, and when Fawful asks Ludwig if he is willing to form an alliance with him once he becomes king, he accepts. In Neo Bowser City, Junior attempts to give the Koopa Kingdom an inspirational speech so that he can convince them to help him find the Age Mushroom and save Bowser, but he is met with booing due to being hoodwinked by Fawful into leading him to the airship. The speech is interrupted by Ludwig who hacks into the television screen behind him and begins telling the kingdom that Junior is the direct cause for all of their problems, and once he lies to the kingdom by saying that Junior was working with Fawful by showing them the selfie that Fawful took earlier, he gains their trust by saying that he is planning to form an army to fight Fawful with and that recruitments are being held at the Tower of Yikk at midnight, and the kingdom marches off leaving Junior in their dust. Hammer Bro., who is also hoodwinked by Ludwig's lies, departs in the airship without Junior saying that he doesn't take orders from traitors, but just when it seems like Junior is all alone, Kamek and an infant Bowser show up in the Koopa a Clown Car and are willing to fight alongside him, and they conclude that Fawful and the Age Mushroom are at the Tower of Yikk and set out for that place. After Fawful congratulates Ludwig for his performance, he heads for his office where the Age Mushroom resides along with several other mushrooms, and he activates a strange type of machine to begin the next part of his plan. That night, Junior has a dream where he is met by Kylie who turns into Fawful immediately afterwards, and he is soon surrounded by an army of Fawful clones along with the sun which takes Fawful's image as well. Junior awakens from his nightmare when he notices Kamek trying to feed Bowser his dinner with no success, so Junior uses Kamek's sceptre to take an infant Bowser's appearance before successfully feeding him by using a method that he used on him when he was a baby. The Clown Car soon approaches the Tower of Yikk, and the kingdom is told that only ten recruits at a time are allowed to enter, but when Hammer Bro. and nine others enter the recruitment booths they are suddenly taken to a factory within the tower where Fawful's machine is located, and once the machine places masks on their faces they become possessed and join the army of countless others that have already been possessed. Fawful, viewing everything from his office, is left overjoyed at the success of his plan, for he lied to Ludwig and was just using him to get the kingdom over to his side, and he plans to use his new army to conquer all of the kingdoms the next morning. Junior and Kamek fly around the tower and witness more of the Koopas being possessed, but because of Kamek's poor eyesight, Junior records what he sees with his phone to show him later on, and they soon find Ludwig's room when they hear him playing "Junior will die" on his piano, but once they break into the room they are ambushed by Ludwig who begins choking Junior until he shows him the video he recorded, causing him to realize that Fawful lied to him. After Junior and Kamek explain everything to him, Ludwig, filled with remorse, decides to join forces with them to find the Age Mushroom and save Bowser, but they need to get past Midbus and the Rejuvenation Beam first, so Junior begins thinking of a plan.