Derzerb appears along with the rest of Team Five when Agito Makishima attempts to liberate the Segawa siblings from Relic's Point. His tremendous physical strength proves to be too much for Guyver-III to handle and Guyver-I fares no better when he shows up. Later on, when Cronos discover where the Guyvers are hiding out, Derzerb and Gaster attack the hideout. Masaki Murakami uses his telepathic ability to try and take control of both Hyper-Zoanoids and force them to kill each other, but Dr. Barcas uses his own superior psychic powers to snap them out of it.
Much later, when Aptom invades Relic's Point to go after Team Five, Derzerb and ZX-Tole are forced to fight him after he has absorbed both Elegen and Gaster. They appear to kill him, but Aptom has found a way to copy himself and his duplicate grabs Derzerb's leg. ZX-Tole vaporises the Aptom duplicate with his bio-beams, but the creature's cells have already invaded Derzerb's body and assimilate him from within.
Derzerb meets a different fate in the 12-part Guyver OVA. He and his comrades first appear when Richard Guyot assumes command of Cronos Japan and attack Sho's high school in order to force the Guyver into a confrontation. In the sixth episode, Derzerb and Elegen are attacked by Guyver-I after he regenerates inside the Cronos Japan building. Derzerb relishes the opportunity of killing the Guyver again and charges him, but the Guyver is unbound by its host's consciousness at that point and manages to overpower the Hyper-Zoanoid. After fracturing Derzerb's facial exoskeleton with its Sonic Buster, the Guyver pushes him across the corridor and out of the window. Apparently, Derzerb's incredible muscle mass couldn't save him from a 50-storey drop.
- Strength - Derzerb is virtually pure muscle, possessing over 60 times the strength of a normal human being. His skin cannot be damaged by any known weapon.
- Heat Absorption - Derzerb can absorb thermal energy, making laser attacks useless against him.
- Pyro Breath - Using the thermal energy he absorbs, Derzerb can discharge waves of fire that can completely incinerate foes, leaving not even ash behind.