Tartarus

Tartarus is a Primordial God of Abyss in Greek mythology, who joined Hades and the Alliance of Hell to eliminate the DxD team, Longinus users, chief-gods of each mythology, and Ajuka Beelzebub.

Appearance
Tartarus is a hundred meters sphere with many eyes and tentacles and after his defeat, his body was reduced to five meters. His body gives out a unbelievable aura and his presence also gives out a dark mist.

History
At some point, Tartarus received a invitation by Hades to join the Alliance of Hell.

Red Dragon Emperor of the Blazing Truth × White Dragon Emperor of the Morning Star: The True Dragon(s) of the Kuoh Academy
Tartarus was mentioned in Volume 24, who were arriving in the Realm of the Dead for Hades’s meeting with the Alliance of Hell.

Tartarus made his first appearance in Volume 25, where he calls to a unnamed God of Death to remind him that a human’s curse is much scarier than God’s curse and Mitsuya Kanzaki attained his Balance Breaker of his thirteenth Longinus, Telos Karma.

In True Volume 2, Tartarus participated in the meeting the meeting of Alliance of Hell with the exception of Erebus and Nyx, causing Tartarus to laugh as primordial gods like to do pranks. When Hades shows the recording of a silver humanoid, Tartarus believed that they are some misses even on the information that only the chief-gods know and it’s outside of their calculations.

In True Volume 3, Tartarus appeared after Erebus was defeated by Issei and revealed that he was watching the fight behind the scenes weather Erebus’plan worked or not, and revealed his goal to sink his enemies into his Abyss. Seeing the Longinus users in the Dimension Lost, Tartarus determined that it was perfect opportunity to sink them in the Abyss after watching Erebus, Gressil, and Sonniellon being defeated by the Longinus users, considering them a great threat. When he was asked by Issei if he was going to kill them, he revealed that he was going to seal them in the Abyss rather than killing them as the Sacred Gear System will make new owners if the previous Sacred Gear users is killed. As Issei was calling out to Ddraig, Tartarus suggested that Erebus used the darkness incantation on Issei’s armor to prevent him from summoning Ddraig and was called out by Kunou for attacking their world, despite being a god. As Kunou’s necklace summons Ophis and Lilith, Tartarus was preparing to fight against Ophis until she clarified that she wasn’t her opponent but it was Issei Hyoudou, who has combined with his familiar Ryuuteimaru to create Apocalypse AnswerArms, which catches Tartarus’s interest and begins attacking Issei with his countless shots of godly aura but it was blocked by the Revelation Barrier. When Issei gonna use the Revelation All-Range Blaster on Tartarus, he deployed defensive magic circles to protect himself, but the blast easily destroyed the defense and took huge amount of damage that half of his body was blown up and started to regenerate himself. Deciding to attack Issei head on, Tartarus used his arms to attack Ryuuteimaru's body but his was cut down by Issei’s four armed Revelation Blade, forcing Tartarus to takes a distance to regenerate his arms and stated he has to fight a ridiculously atrocious existence. He used his aura attacks rain everywhere in the area with Ophis and Lilith protecting everyone, and gets a lecture from Issei as Ddraig finally manifested to combine their attacks with Tartarus shooting aura beams from his countless hands and eyes until Ddraig dodged it and managed to hit Ryuuteimaru. His arms was cut downed by Issei’s blades and was punched in the giant globe full of eyes and chased after Ddraig until he was burned by his flames and eventually defeated by the combined efforts of Issei’s Revelation All-Range Blaster and Ddraig’s flames. After his defeat, Tartarus was tattered and reduced roughly to five meters and his eyes were closed.

Powers & Abilities
Abyss: Tartarus has the ability to seal his enemies into the abyss and doesn’t kill them, it can prevent Sacred Gears from being transferred to new owners.

Defensive Magic: Tartarus can deploy defensive magic circles to protect himself from harm.

Immense Durability: He possesses a strong endurance from very powerful attacks such as Revelation All-Range Blaster that blew half of his body and his arms being cut off Issei’s blades.

Regeneration: Tartarus is shown with the ability to regenerate half of his body that was blown off, and his arms that was cut by Issei’s Revelation Blades.