Longinus

The Longinus (神滅具（ロンギヌス） Ronginusu) also known as Tools that Destroy God are the thirteen top-tier Sacred Gears with enough power to kill Gods.

Summary
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, only nine have appeared in the series thus far, 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.

Trivia

 * Out of the thirteen Longinus, four of them are held by members of the Khaos Brigade, three of which are wielded by Cao Cao's Hero Faction, all of those three being top-tier Longinus.
 * 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.
 * Out of the thirteen Longinus, three of them are known as the Holy Relics, they are: the Holy Spear - True Longinus, the Holy Grail - Sephiroth Graal and the Holy Cross - Incinerate Anthem.
 * 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.