This class of Sacred Gears is specifically named after the True Longinus, the first and most powerful, and unlike other Sacred Gear, that has more than one of the same type, the Longinus are utterly and completely unique, and only one of each may exist at a time. It is stated that all Longinus is just a combination of one ability with another. Essentially, they combine powerful abilities that aren’t supposed to be combined.
Out of the known thirteen, ten have appeared in the series thus far (with another one appearing in another fanfic), but Mephisto has mentioned that due to the abnormality on the Sacred Gear system, and the Sacred Gears' ability for growth and change, more Longinus might be born.
The True Longinus (黄昏の聖槍, Tōrū Ronginusu), also known as the Holy Spear, the Spear of Destiny, or the Holy Spear of the Setting Sun. It is the first and most powerful Longinus, as it is the same spear that St. Longinus used to stab Jesus Christ, as well as one of the Holy Relics. It is currently wielded by Seren, the leader of the New Hero Faction.
Zenith Tempest (煌天雷獄, Zenisu Tenpesuto) also known as the Prison of Bright Heavenly Thunder, is the second-strongest Longinus. It has the ability to control the weather and its elemental attributes. It's current possessor is unknown.
Annihilation Maker (魔獣創造, Anaiareishon Mēkā), also known as the Creation of the Demonic Beast, is a high-tier Longinus with the ability to create any creature that the possessor can imagine. It is currently wielded by Adolf Medici of the Alba Team.
Dimension Lost (絶霧, Dimenshon Rosuto), also known as the Fog of Extinction, is a high-tier Longinus with the ability to block any attack using the mist that it creates, and transport anything inside the mist to any location. It is currently in possession of Dame Du Lac of the Alba Team.
Boosted Gear (赤龍帝の籠手, Būsuteddo Gia), also known as the Red Dragon Emperor's Gauntlet, is a mid-tier Longinus, where the Welsh Dragon, Ddraig, resides in. The gauntlet has the ability to enhance the user's capabilities as well as transferring power to anyone or an object. It is currently wielded by Ayato Hyoudou, a genetic clone of Issei Hydoudou and the queen of Shelia Gremory's Peerage.
Divine Dividing (白龍皇の光翼, Dibain Dibaidingu), also known as the White Dragon Emperor's Light Wings, is a mid-tier Longinus where the Vanishing Dragon, Albion, resides in. The wings not only give the ability to fly but can also halve the power from anything or anyone, which is then added to the user. When the power surpasses the user's limits, the excess energy gets expelled out through the wings. It is currently wielded by Elizabeth Lucifer, the granddaughter of Vali Lucifer.
Regulus Nemea (獅子王の戦斧, Regurusu Nemea), also known as the Lion King's Battle Axe, is a battle axe Longinus that contains the spirit of the Lion King, the Nemean Lion Regulus, residing within it. It has the ability to split the earth in one swing, and it also protects the user against any projectile attacks that are used against the owner. It is currently wielded by Raylan Givens.
Canis Lykaon (黒刃の狗神, Keinesu Ryukaon), also known as the Inugami of the Black Blade, is a Longinus that takes the form of a huge black dog with red eyes. According to Kurumi, her Longinus is an independent avatar type and has its own instinct. It has the ability to produce blades from his body and can transform itself into a sword. It can also attack through shadows. Its current wielder is Kurumi Ikuse, the daughter of Tobio Ikuse and Sae Toujou.
Sephiroth Graal (幽世の聖杯, Sefuiroto Gurāru), also known as Holy Grail of the Secluded World is a Longinus, it is the "Holy Grail" from the Last Supper that Christ used and the Grail of Arthurian legend, it's also one of the Three Holy Relics. Its current wielder by Valerie Tepes, although its in the form of a sub-species where she has a total of 3 Holy Grails instead of one.
Incinerate Anthem (紫炎祭主による磔台, Inshinerēto Ansemu), also known as the Chief Mourner’s Crucified Stand of Purple Flame is a Longinus that is one of the Three Holy Relics, the Incinerate Anthem, is the "Holy Cross" on which Christ was crucified. It has the ability to generate and control purple colored Holy Flames that can incinerate Devils. This particular Longinus has a will of its own, allowing it to move independently, and even remove itself from its current wielder to a more suitable one. It is currently wielded by Lucan 9, an Artificial Human made from the genes of the butler of King Arthur, Sir Lucan.
Absolute Demise (永遠の氷姫, Absoryūto Deimaizu), also known as the Eternal Ice Princess, is a Longinus that can materialize a three-meter tall doll made of ice that takes a form of a woman in a dress. Its current possessor is Bella Hyoudou, a genetic clone of Issei Hydoudou.
Innovate Clear (蒼き革新の箱庭, Inobēto Kuria), also known as the Miniature Garden of the Green Tree of Innovation, is a Longinus who's abilities are said to be an idealized version of both Dimension Lost and Annihilation Maker, the ability to create an artificial pocket universe that can create and support life; However, anything created in there can only live in that universe. It is currently in possession of Ichijou Nakiri, the son of Ouryuu Nakiri and Millarca Vordenburg.
Telos Karma (究極の羯磨, Terosu Karuma), also known as the Ultimate Karma, is a Longinus with the ability to wrap probability, creating outcomes that otherwise would not be possible. In the past it has also been nicknamed "History Breaker". It's current possessor is unknown.
Nereid Kyrie (果てしない緑の海の詩, Nerīde kirī) also known as the Poem of Endless Green Sea, is a high-tier Longinus that is currently wielded by Ingvild Leviathan, the inactive Queen of late Issei Hyoudou. It has the power to control and strengthening dragons as well as the sea.
Star Buster Star Blaster (スターバスタースターブラスター, Sutā Basutā Sutā Burasutā) also known as the Star-Crushing Sword and Star-Piercing Gun, is a high-tier Longinus, with the ability to fire highly-destructive blasts of light, with Kurenai stating it felt like facing a supernova head on. It is currently wielded by Fallen Star. It’s a two in one Sacred Gear of a sword and rifile.
Sun Striker Moon Defender (サンストライカームーンディフェンダー, San Sutoraikā Mūn Difendā) also known as the Sun-Breaking Cannon and Moon-Shielding Barrier, is a high-tier Longinus, with the abilities to fire flaming cannon shots (Sun Striker), and create barrier and shields of shadows (Moon Defender). It is currently wielded by Eclipse. It’s a two in one Sacred Gear of a shotgun and shield.
Aeon Balor (イオンバロール, Ion Barōru) also known as The Evil-Eyed King Who Dominate the Space and Time, is a high-tier Longinus that is currently wielded by Gasper Vladi. It has the ability to stop a person's time, manipulate darkness and can allow the user to peer into other timelines. It was formerly known as Forbidden Balor View until it has evolved into a Longinus.
Turin Image (幻想の聖骸布の布, Torino Imēji), also known as the Shroud Cloth of Illusionary, is a mid-tier Longinus as well as one of the Holy Relics. It has the ability to cast almost life-like illusions of the possessor, and can generate barriers of light. It is currently wielded by Reya Gadreel.
Alphecca Tyrant (アビスの比類のない王冠, Arupeka Tiranto), also known as the Unparalleled Crown of the Abyss is a mid-tier Longinus that has the ability to create extremely bright orbs of light, that the user can use to blind and burn opponents or to see in the dark. It is currently wielded by Serena Sitri, the daughter of Sona Sitri and Genshirou Saji.
Unknown Dictator (未知の独裁者, Michi no dokusai-sha) also known as the Imperial Child of Machine World, is a mid-tier Longinus with the ability to control iron and electronic devices. It can also create mechanical equipment, and is currently wielded by Mordred Pendragon.
Melody of Will (ウィルのメロディ, U~iru no merodi), also known as the Heavenly Anthem of Control is a high-tier Longinus that has the ability to take control of several people and creatures at once, and if mastered other Sacred Gears. It is currently wielded by Melody, the sub-leader of the New Dante Faction.
Billion Blades (無制限刃作品, Birion Burēdo), also known as the Unlimited Blade Works, is a Longinus with the ability to create countless swords of Holy, Demon or Holy-Demonic nature, with various attributes. It is currently in possession of Shirou Muramasa.
Boosted Gear Diabolus (籠手の赤龍帝皇太子, Būsuteddo Gia Diaborosu), also known as the Gauntlet of the Red Dragon Emperor Crown Prince,is an Artificial Longinus created by Kurenai Himejima that is based on the Boosted Gear. It has the same ability as the original, which is to boost his capabilities, but is still unstable so the user must be careful to not overuse it. It is currenty wielded by Ex Gremory, the son of Issei Hyoudou and Rias Gremory.
Gigantis Maiden Robe (天国の襲撃の黄金のドラゴン君主, Gigatisu Meido Rōbu), also known as the Heavenly Raiment of the Golden Dragon Monarch, is an Artificial Longinus with Fafnir as its power source. This acts as a sort of alternate version to the Down Fall Dragon Spear. It is currently wielded by Airi Hyoudou, the daughter of Issei Hyoudou and Asia Hyoudou.
Typhon's Dagger (王の怪獣短剣, Taifon Dagā), also known as the King of Monster's Dagger, is an Artificial dagger Longinus that uses Typhon as its power source. It also appears to be based on the Down Fall Dragon Spear. It is currently wielded by Asia Demiurge, the daughter of Shemhazai.
Sanctum Archfiend (煉獄の獣に乗る, Sankutamu āchifīrudo), also known as the Ride of the Purgatory Beast, is an Artificial Longinus in the form of a car (more specifically, a modified 1969 Dodge Charger) engulfed in hell flames. According to Robbie, his Longinus is an independent avatar type and has its own instinct. It is currently wielded by Roberto "Robbie" Reyes, better known under the alias of Arcus from the Fallen Angel organization, Grigori.
Absoluto Dawn (食竜の球体, Abusoruto dōn), also known as the Eclipse Dragon's Orb, is an Artificial Longinus in the form of a orb, that uses a tamed version of the spirit of the Eclipse Dragon, Apophis as its power source. It also appears to be based on the Longinus, Absolute Demise. It is currently wielded by Glacies Hyoudou, a genetic clone of Issei Hydoudou.
Wire Tails (無限の絹と創造の糸, Waiyā Teirusu), also known as the Infinite Silk and Threads of Creation, is an Artificial Longinus that uses Arachne as its power source. It is currently wielded by Karma of the Fallen Angel organization, Grigori.
The Longinus Canis Lykaon is a reference to the scientific name of the Eastern Timber Wolf (Canis lycaon), a wolf that lives in Eastern Canada. It may also be a reference to Lycaon, the man that was turned into a wolf by Zeus as punishment for feeding him Nyctimus, Lycaon's own son. The form and the backstory in Slash/Dog, however, is similar to the Chinese Tiangou.
The name Longinus is based upon the legendary and mystical figure of Christian mythology. Longinus, according to multiple Christian communions, is said to have been the soldier who pierced Jesus' side with a lance.
The Artificial Longinus, Boosted Gear Diabolus, Gigantis Maiden Robe and Typhon's Dagger, were originally from the special novel, High School DxD Ex, which was bundled in with the Blu-Ray volumes of High School DxD BorN.
Three of the Four High-Tier Longinus user's have been named so far.