This class of Sacred Gears is specifically named after the True Longinus, the first and most powerful, and unlike other Sacred Gears that have more than one of the same type, the Longinus are utterly and completely unique, and only one of each may exist at a time. Azazel has stated that all Longinus are just a combination of one ability with another. Essentially, they combine powerful abilities that aren’t supposed to be combined.
Out of the thirteen, eleven have appeared in the series thus far (with another one appearing in another series), but Azazel 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 kill Jesus Christ. as well as one of the Three Holy Relics. It is currently wielded by Cao Cao.
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 is currently in the possession of Dulio Gesualdo, the most powerful exorcist who was reincarnated into an Angel as Michael's Joker.
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 was wielded by Leonardo of the Hero Faction until Volume 12 where it was confiscated by Indra.
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 was wielded by Georg of the Hero Faction until it was confiscated by Indra in Volume 12 following the latter's defeat at the hands of Gasper Vladi.
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 enhances the users capabilities as well as transferring power to anyone or object. It is currently wielded by Issei Hyoudou, a member of the Occult Research Club and the Pawn of Rias 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 one which is the added to the user, and when the power surpasses the users limits, the excess energy gets expelled out through the wings. It is currently wielded by Vali Lucifer of the Vali Team.
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. The Regulus Nemea is currently a part of Sairaorg Bael's Peerage as a Pawn, so Sairaorg is considered as its wielder.
Canis Lykaon (黒刃の狗神, Keinesu Ryukaon), also known as the Dog God of the Black Blade, is a Longinus that takes the form of a huge black dog with red eyes. According to Tobio, his 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 Tobio Ikuse, better known under the alias of Slash Dog from the Fallen Angel organization, Grigori.
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 will of its own, allowing it move independently even removing itself from its current wielder to a more suitable one. It was previously owned by Walburga. It's current wielder is Lint Selzan (a girl who looks like Freed) who join Rias's Team in Azazel Cup as a knight.
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 a blonde girl named Lavinia Reni and is currently a member of the Magician's Association as well a member of Tobio's Slash Dog Team.
Four of the thirteen Longinus contain powerful creatures, of which three have had roles in the storyline.
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.
During the "Kyoto Incident" in Volume 9, the original Sun Wukong tells Georg that he needs to talk with his Longinus to better grasp its abilities. This suggests that the remaining Longinus that don't have a creature sealed inside them, instead have some other form of consciousness.