While Red Son was making the final adjustments to free the Demon Bull King, he and Princess Iron Fan notice Bob attempting to pull the Golden Staff off a mountain but failed, as his arms were ripped off. Red Son remarked that only people who are deemed worthy can lift the Monkey King's staff but created a Power Glove that is able to lift the staff for those who can't. After Red Son noticed nothing happened after he pulled the staff off the mountain, he questions Princess Iron Fan if she knew what mountain trapped the Demon Bull King until the aforementioned person was freed. When Demon Bull King asked Princess Iron Fan on how she freed him, Red Son interrupts by stating that he was the one who freed him and said that the Demon Bull Family will spread the world in darkness until MK accidentally falls on him. Enraged, Red Son gets mad at MK and decided to kill him to show the Demon Bull King how powerful became during the past five hundred years. However, when MK block Red Son's punch with the staff, the latter decided to take the staff by force, but only to be defeated when MK used the staff again. After MK escaped, Red Son went after him by using his Inferno Truck.
By using the Inferno Truck and Race Car, Red Son chases MK across the City until he crashes to a restaurant.
After failing to get the Golden Staff, Red Son builds the Demon Bull King a special kind of armor that is able absorb energy to create energy and explains it to him.
At a Shoe Store, Red Son asked an assistant for the latest shoes for him and the Demon Bull King. Moments later, he watches the Demon Bull King absorbing most of the shoes after being told to go to the back of the line.
After being told that MK's Team went to Flower Fruit Mountain by General Ironclad, Red Son gets mad him for letting them get away until Princess Iron Fan arrived, saying that she'll get the staff. Later, Red Son watches Princess Iron Fan returning with the Golden Staff and the Demon Bull King being empowered by it.
After MK's Team returned to the City, Red Son attempts to fight them until being hit by the Cloud Jet. When the Demon Bull King was defeated, Red Son tells MK to face him without the Monkey King Warrior Mech but passed out and Princess Iron Fan rescued him and the Demon Bull King.
At the Flaming Foundry, the Demon Bull King takes his anger out by destroying parts of the foundry until Red Son says that he'll help him get the power he deserves before heading out.
With the help of the Bull Clones, Red Son breaks into the Weather Station to control the City's weather so he can return the Demon Bull King to his former glory. When MK and his team arrives, Red Son watches MK accidentally hurting Mei and Sandy and knocking himself out of the Weather Station, allowing Red Son and the Bull Clones to capture the team.
After MK returned to the Weather Station, Red Son engages in a fight with him until he was able to defeat him. However, MK was able to use the Golden Staff to hang Red Son and the Bull Clones outside on top of the Weather Station and zapping them when he presses the lightning button. After being defeated, Red Son insults MK before leaving.
Red Son can be described as a stereotypical insane boy genius/mad scientist, creating a multitude of weapons to aid the Demon Bull Family in their rise to power. He greatly admires his father for his strength and seeks to serve him and any possible manner for his family to rule the world. Befitting his maniacal personality, he is also yields a short, and literally fiery temper, prone to outbursts of rage whenever things do not go his way, or he finds himself challenged by those he deems inferior to him.
Red Son looks akin to an average human teenager, with red hair tied into a ponytail and part of his raised at the front end and a yellow highlight resembling fire. He also has a 'X' shaped scar on his cheek. He wears pince-nez glasses, a red long-sleeved trench coat that is torn at the ends over a black shirt, indigo pants with a purple belt, silver buckle and yellow pocket linings.