Abaddon is a biblical term in Hebrew which means "place of destruction" and is a fiery plain in the realm of the dead, Gehenna. In the later teachings of Revelation, Abaddon had become a being that personified the abyss, becoming known as the "Angel of the Abyss." He is often depicted as a large, human-sized locust and leads a swarm of locusts and other insects that carry infectious diseases. In this respect, he is often associated with the swarms of locusts that sometimes destroy entire crop fields and in the The Greater Key of Solomon was said to be called upon by Moses to cause the great rains during the Ten Plagues of Egypt.
While in many circles he is considered to be associated with Satan, even going as far as to claim that Abaddon is another name for Satan, he is actually a righteous figure, and was charged with casting Satan down into the abyss and sealing him within.
The Center of Tokyo Millennium used Abaddon (Michael claimed he would be restored as an angel for doing so) to swallow Valhalla. Later in the game, Aleph enters Abaddon's body and fights his heart after using Mekata's MAG Presser to reveal it.
Abaddon appeared in the Hush-A-Bye Devil battle in Imagine's 6th Anniversary event as the secret final event boss accessed through Door-666. Unlike the other event bosses, his endchest did not drop his summon PG and he has yet to be made available as a player demon through any means. In January of 2014, alternate Shinjuku Babel was added as a permanent zone, with Abaddon returning as a boss. He is one of the few enemies that has the ability to enter stealth mode mid-combat, allowing him to recover and prepare to emerge with a surprise attack. Like many of the alternate Babel bosses, he has two forms-- the stronger form spawning after the first is defeated. The second form in Abaddon's case can either null all physical attacks at a high level or null all magical attacks at a high percentage, making a varied party for this instance important.
"The king of the abyss that appears in the Book of Revelations of the New Testament. He controls locusts and plagues. He leads the seventh order of demons who appear at the sounding of the fifth trumpet on Judgement Day, when he will bring a horde of locusts to make people suffer. His name in Hebrew means "destroyer" and "endless pit." It's thought that his origins lie in the deification of the natural disasters caused by locust swarms."
—Shin Megami Tensei IV Profile
Abaddon appears in the New Game Plus Challenge Quest, Help Me Exterminate the Demons. He appears as a red foe alongside the 18 Manticores in Shinjuku National Park that must be slain and is the demon said to be attacking them. Defeating him is optional.
Merkabah also refers to him in the Law ending, referencing both his role in Shin Megami Tensei II and his position as the Angel of the Abyss, when activating the Yamato Perpetual Reactor to create a black hole to swallow Tokyo.
Abaddon was first used against Shadow Naoto in an attempt to slow down and damage her. Abaddon shot Arrow Rain at her in this attempt but failed and missed every strike. Abbadon is the Persona that represents Yu and Shu Nakajima's bond in Persona 4 The Animation.
In the True Ending special, Abaddon appears to attack Margaret'sLoki using Arrow Rain, as well as bring a message of thanks from Shu to Yu.
Abaddon is a boss in Black Book. He attempts to strike down Setsuna Kai in his masters name, only for Cool to take the hit for him. Out of respect for his fellow demon, he decides to spare the Devil Child for now. He can later be recruited in the Pyramid.
Abaddon is one of the minions of Lucifer and is usually seen alongside Fenrir. The two demons are good friends and usually oversee the actions of the latest possessed demon. After Lucifers defeat the two begin working for Vibhishana, Paimon, and Demogorgon until they learn Lucifer is still alive. The two of them then proceed to try to aid their master in his imprisoned crystal state.
Abaddon appears during the last encounter with the Tribhvana. Serph's party finds Tribhvana:Earth alone in a room with a bloody mouth in B13 of the EGG Installation. Upon Cielo questioning him about the whereabouts of his partners, Earth reveals that in a moment of twisted inspiration he devoured his comrades to gain strength. Angered by this, Cielo will force his way into the party for the confrontation with Abaddon.
Abaddon has three 'forms' which fill the roles of all three Tribhvana members (physical attacks, magic, and support) and will switch between them using the Bellow skill. He also gets a minimum of three turns per round. His resistances for each form are the same as each member of the Tribhvana. Low level spells will hardly damage Abaddon so learning Agilao, Zanma, Terazi, and Diarama is recommended. Elemental Boosts will also help. Abaddon will actively try to target weaknesses during the magic phase so shield spells will also help.
One dangerous ability Abaddon has is to swallow a party member, leaving the party with less actions to take and if both members die before they are released it will be a game over.
"The king of the abyss that appears in the Revelations of the New Testament. He controls locusts and plagues. He leads the seventh order of demons who appear at the sounding of the fifth trumpet on Judgement Day, when he will bring a horde of locusts to make people suffer. His name in Hebrew means "destroyer" and "endless pit." It's thought that his origins lie in deification of the natural disasters caused by locust swarms."