Black Temple

The Black Temple was a location in the Underworld within the DxD: Ascension series. It housed the Titan Core, a mysterious artifact with unknown power, and was home to individuals who have worshipped a variety of deities in its history. It was managed by Rizevim Livan Lucifer, disguised as "Temple Master Revan," until the temple grounds were invaded by the Khaos Brigade and destroyed.

History
The Black Temple has existed since at least the time of the Great War between the Three Factions, though many believe it was built since before then. As early as anyone remembers, the cultists living there worshipped a being known as the Leviathan God, though little is known about this deity. Some theorize that it's an alternative name for the original Leviathan, while some claim it to be the first member of the species named after the late Satan.

In the years since then, the temple has begun worshipping the original Lucifer as well, though worship of the other two original Satans is noticeably absent. Sirzechs believes that this is because of Rizevim's influence.

Rizevim Livan Lucifer took control of the Black Temple about 72 years before the start of the series, after he murdered the guards keeping him under house arrest and disappeared. He went to the temple and quietly disposed of the previous master of the temple and established himself as Revan, the cultists' new leader. For the vast majority of those years, Rizevim lived rather peacefully at the temple. The only relevant change he made was introducing the worship of his father. However, when he was recruited to the Old Satan Faction of the Khaos Brigade, he transformed the temple into a front for their activities.

About 20 years before the start of the series, Rizevim had a giant arena built using some of the empty space on the temple grounds and started hosting annual tournaments there, which were exclusive to devils for almost all these years. "Worthy" participants were invited to the temple to compete for glory and the occasional fortune if Rizevim was feeling generous that year. Winners were often propelled to the pinnacle of devil society and flooded with sponsorship offers, requests for product endorsements, and the like. Once the DxD alliance was formed, members of all participating factions were able to be invited to the tournament.

Shortly following said tournament, in the year 2017, the Khaos Brigade attacked the temple, destroyed almost everything except the main cathedral, and killed almost all the residents. The assault was eventually stopped by Zach Praktum and his friends, who then revealed Revan as none other than Rizevim Livan Lucifer. Rizevim destroyed the cathedral, finishing off the last two surviving cultists and officially putting an end to the Black Temple.

Overview
The Black Temple is mostly located atop Mount Leviathan, the highest mountain in the Leviathan Peaks. It consists of numerous residential buildings for the cultists, a few blacksmiths, other tradesmens' shops, a massive ultra-modern arena, a hotel for tournament contestants, and a giant cathedral. Most of the buildings are constructed out of "nightstone," a material said to be made from the bones of Nyx.

The temple also has a massive network of heavily guarded underground tunnels. Nobody knows what's hidden down there, other than Rizevim's study and a meeting room for Khaos Brigade members.

The temple is surrounded by a high outer wall and was guarded by a very old wyvern before she went out in battle against Zach and his team.

Residents

 * Rizevim Livan Lucifer (formerly)
 * Various human cultists
 * Various devil cultists
 * Various fallen angel cultists