Apollyon (深淵 Aporuon) (also:Apollon) is a mysterious being who wears a unique black armor. He has begun to collect Zoacrystals and was so far able to gather all crystals of the fallen Zoalords as well as the one of Edward Caerleon, who he defeated in battle. During this battle Apollon used the same abilities as Caerleon, hinting that he might be as powerful as Archanfel, as Caerleon stated that only Archanfel can use his powers. His armor appears to be made from the same material as the Guyver's control metal. It is thus theorised that he is an agent sent by the Ouranos.
He later encountered Richard Guyot where Apollon revealed his name and that he had no interest in Guyot's fake Zoacrystal. Afterwards, he attacked a cloaked Aptom and kidnapped Tetsuro Segawa along Mizuki Segawa at the Odagiri Mansion.
When Apollon originally appeared, he announced himself as 'the harbinger of destruction', leading some to transliterate his name as Apollyon], after the Biblical angel of the abyss from the book of Revelations; later, this was changed to Apollon, the Greek name of Apollo - the son of Zeus, maintaining this particular naming pattern.