Gulus Realm Burst

Gulus Realm Burst (グルスレルムバースト, Gurusu Rerumu Bāsuto), also known as GRB, is an infection originating in Regulusmon's body, that increases a Digimon's survival instincts and fighting power. It is said that Digimon infected with "GRB Factor" have their personalities altered and become frenzied. Simulations also show that if large amounts of the GRB Factor are injected into the Digimon that produces it, it will evolve into Arcturusmon.

Digimon that produce the GRB Factor

 * Regulusmon
 * Arcturusmon
 * Gulus Gammamon (anime only)

=Appearances=

Before leaving the Digital World, Gulus Gammamon released a small amount of the GRB Factor through Gammamon's body, gradually leading to the infection of the Digital World's own environment and the Digimon.

As revealed by Gulus Gammamon in, the purpose of causing the infection was to create an army strong enough to face the "Endbringer", the entity responsible for destroying his home planet.

Infected Digimon
Although it is mentioned that several different Digimon were infected, only a few were shown in the series, which are:

=Trivia=
 * The concept and terminology is a reference to, flashes of gamma rays that are the most energetic and luminous electromagnetic events in the universe.
 * In Digimon Ghost Game, the infected also share the characteristic of their natural body color being replaced by Gulus Gammamon's color pattern.
 * Regulusmon's speech during his fight against Bloom Lordmon in, suggests that the GRB Factor would be able to provoke a new evolution in those who adapt to survive.