The Ultimate 4 are the supporting antagonists of Digimon Universe: Appli Monsters, and are handpicked generals of the evil Leviathan.
Biomon is a robotic-like Appmon. Defeated by Revivemon, but killed by Charismon.
Beautymon is the only female member of the Ultimate 4. Defeated by Oujamon.
Fakemon is a clown-like Appmon who loves to make deceptions. Defeated by Entermon.
Charismon is the leader of the Ultimate 4, and the most pure evil member of all. He resembles a dark version of Globemon. Destroyed by Globemon.
The Ultimate 4 first appear when they were gathered by Leviathan to aid Knight Unryuji after he became the new CEO of L-Corp. They watched as Knight unleashes an L-Virus infected Batterimon over L-Town to attack the Applidrivers.
Later on, the Applidrivers show up to confront the Ultimate 4 after Eri refuses Knight’s offer to work with Leviathan. They brutally killed the Applidrivers buddies, but luckily Yujin and Shutmon quickly sent them back to Earth before the Ultimate 4 could kill them.
After the Applidrivers found their Appmon buddies resurrected and reunited with them, Biomon summoned previously defeated evil Appmons as ghosts from the past as well as a ghostly Sukasimon. After the Applidrivers defeated the ghosts, they confront the Ultimate 4 again.
Firstly, Torajiro and Entermon fought Fakemon and defeated him, gaining his Appli Drive. Then Eri and Dokamon fought Beautymon and defeated her, gaining her Appli Drive. Rei and Hackmon fought Biomon, and after the battle, Rei forced Biomon to tell him where his brother, Hajime is located while Hackmon tortures him. After Biomon caves in and tell him where Hajime is at, he is killed by Charismon for giving away the secret.
With the three Ultimate 4 members defeated, Haru and Gatchmon come face to face with Charismon. Charismon almost seemed to get the upper hand, but Haru powered up Globemon and manages to kill Charismon, gaining his Appli Drive, and putting an end to the Ultimate 4 once and for all.