Ultimate 4

The Ultimate 4 (アルティメット) are four extremely powerful grade Appmon and the supporting antagonists in Digimon Universe: Appli Monsters. They are Leviathan's handpicked generals.

History
The Ultimate 4 were gathered by Leviathan to aid Knight Unryuji after he became L-Corp's CEO. They watch as Knight unleashes an L-Virus-infected over L-Town. They later show up to the Applidrivers after Eri Karan refuses Knight's offer of working for Leviathan. They then fought the 4 of them, effectively winning, destroying their Appli Drives, and killing their buddies. Fortunately, Yujin and stepped in and sent the Drivers back to Earth before the Appmon got a chance to kill them.