666 (Trihexa) is a legendary being known as the Apocalyptic Beast and Emperor Beast of Apocalypse. At its full power, it is stated to be on par with Great Red[1] and Ophis. Also, it is the Beast recorded in the Apocalypse[2].


666 has the appearance of a large beast with characteristics coming from different animals like a lion, a leopard, a bear, a dragon, etc. It has seven necks, seven heads, with ten horns, as well as seven long thick tails of different shapes. It also has four stout arms and two legs that are even thicker than its arms. Its main body is that of a primate leaning forward and is covered in black fur and what appears to be scales all over its body. Its size is well over several hundred meters, making it significantly larger than even Great Red.

The appearance of Trihexa's core is described by Issei and Ddraig in Volume 21 as neither having seven heads or having 10 horns, but having the appearance of a young boy who is able to sprout six wings (bird, dragon, bat, and various other beasts) instead.


Not much is known about its personality other than the fact it has only one nature and that is to destroy everything including the Underworld, Human World, Heaven, and all other mythological worlds. It's possible that it is completely mindless, only instinctively knowing to destroy everything. Its homicidal nature, combined with its immense power, made it immensely dangerous to the point that the God of the Bible had to risk his own life by using numerous forbidden seals to seal it away to prevent it from endangering the World.

Despite its supposedly savage nature, it seems to have an interest in Great Red and Ophis. This is evidenced by how it was attracted to Issei upon sensing their power in him. This could be because both Great Red and Ophis are beings on par with Trihexa.


At some point in the past, the God of the Bible confirmed the existence of 666 that was thought to be unknown and placed thousands of forbidden seals on it, sealing it at the "end of the world". In Volume 16 however, it was revealed that Rizevim and Qlippoth found 666 by using the Sephiroth Graal's ability to come into contact with the principle of life and decided to unseal him with the power of the Holy Relics[1].


The Legend of Oppai Dragon and his Lively Companions

666 was mentioned in Volume 16 by Rizevim Livan Lucifer who then reveals his goal to unseal Trihexa through the use of the Sephiroth Graal and Incinerate Anthem to pit him against Great Red.

In Volume 20, 666 first made its first appearance when it was found by the trio of Azazel, Vali, and Lilith sleeping at the center of the power chamber of Agreas. Rizevim relocated the beast from the end of the world to Agreas and used the crystal inside it as a power source for unlocking the seals placed on 666. This, together with the fruit of life, succeeded in breaking most of its seals. As a last resort in case of Rizevim's death, he used his soul as the final power source to complete the awakening of the Beast. After 666 had fully awakened, it destroyed the ceiling of the floating city and flew up together with an army of mass-produced Boosted Gear Scale Mails[note 1]. 666 and the armors then left the scene with the legendary Evil Dragons, Apophis and Azi Dahaka in tow.

Few days after being unsealed, Trihexa along with the Qlippoth army, dealt massive damage to several of the mythologies, eliminating many Gods in the process. Trihexa later splits its heads into seven bodies, attacking multiple locations including Europe and Japan. Through the efforts of the myths working together, the Sephiroth Graal was reclaimed from Qlippoth and Trihexa had its movement sealed through the magic equation formulated by Rossweisse. Trihexa, however, manages to release all of its cores before its movement was sealed, with one of the cores appearing before Issei. However, despite the core engaging Issei and Sirzechs, the latter who had come for Issei's assistance, both of them failed to deal any damage to the legendary Beast. The battle, however, came to a swift end when Sirzechs along with the leaders of many mythologies sealed themselves with 666 in the Isolation Barrier Field, trapping 666 in the barrier as the Beast now battles the leaders inside the barrier [3].

Power & Abilities

Immense Strength: 666's powers were initially largely unknown due to being sealed for many years. 666 has power on par with Great Red and Ophis in its prime; a clash between both Trihexa and Great Red is feared because of the potential damage it could inflict to the world due to their strength, with Azazel believing that a clash between them, will result in the end of the world[1]. In fact, it is such a true monster that it could easily destroy the entire world on its own. Rizevim stated that it took thousands of forbidden level seals for the God of the Bible to seal it away. Upon gazing it for the first time, Azazel notes that just its aura alone is enough to make a normal person go crazy. According to Shiva, only Ophis at full power and Great Red can destroy it as 666's absolute overwhelming power made it impossible for Shiva, who is an immensely powerful God, to destroy it. In a matter of days after being unsealed, it managed to cause massive damage to multiple mythological factions, nearly completely wiping out Heaven, Grigori, and Asgard.

Fire Breath: 666 can fire a powerful fireball from one of its heads.

High Speed Regeneration: Aside from its nigh indestructible skin, Trihexa possesses high speed regeneration and is able to heal itself in an instant if any parts of its body were damaged, being able to regenerate even if turned to ashes. Due to its immense regeneration, Trihexa can easily survive immensely powerful attacks to the point the Balance Breakers of extremely powerful Longinus Possessors such as Dulio, Tobio, Issei, and Vali could not inflict any permanent damage on Trihexa's body. According to Sirzechs, even with the combined force of the numerous Gods of various mythological factions, Azazel, Michael, and three of the current Satans including Sirzechs, a Super Devil himself, it will take an enormous amount of time to be able to defeat or even seal Trihexa due to its tremendous regeneration powers.

Body-Splitting: Trihexa can split each of its heads into seven different bodies.

Flight: Trihexa is shown capable of flying without wings. Although the core of Trihexa is able to sprout six wings (bird, dragon, bat, and various other beasts).

Mass Boosted Gear Production: With the help of the Khaos Brigade's modifications with the Sephiroth Graal, Trihexa can mass produce Boosted Gear armors. It was gone after Gasper, and Valerie got back her Grail.

Core Expulsion: 666 has shown the ability to release its core. It demonstrated this in Volume 21 when one of its cores appeared before Issei due to Trihexa's curiosity when it sensed both Great Red's and Ophis' powers coming from him.



  • The name "Trihexa" can be broken up into two parts: "Tri" which means "three", and "Hexa" which means "six". So "Trihexa" can be interpreted as "Three Sixes" which can refer to the name of 666, which has three sixes.


  1. The fake armors had the ability to move on their own.


  1. 1.0 1.1 1.2 Highschool DxD Light Novel Volume 16 Life 4 Rizevim Livan Lucifer
  2. Highschool DxD Light Novel Volume 16 Afterword
  3. Volume 21


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