Fan:RB Virus

The RB Virus (ＲＢウイルス), short for Rampage Baron Virus (ランペイジバロンウイルス), is a powerful virus program created by Kumon Kai after his Spirit Core was destroyed by the vengeful Samuel Nakaoka. As his tiny lingering spirit enters the Digimon World, he exacts his vengeance towards Samuel for interfering in his and Kolda's fight. The RB Virus has the ability to infect any Digimon, driving them into berserk states and causing them to endlessly attack one another. Furthermore, Digimon infected by the RB Virus can also infect other Digimon, spreading the virus even further. This virus can even force the RB-infected Digimon to undergo digivolution, essentially resulting in a "mutation" according to Nishima.

Once Beerus discovers the source of the RB Virus, Kumon Kai, under the name as Kaizer Baron reveals himself to be mastermind behind the virus. His goal is to use the RB Virus on every Digimon on the Digital World and become infected and brutally destroys each others as his vengeance to revive himself as a god which angers Samuel Nakaoka and fights him with brute force.