They each possess a great amount of magical energy that show them being things ' outside of normality', miracles exceeding both humanity and magecraft. There are cases as with the Hanging Gardens of Babylon which is possessed by multiple heroes, Nebuchadnezzar II possessing it by deed and Semiramis possessing it by distortion of fact. Most Noble Phantasms will belong only to a single hero, activated only by them, their true owners, by channeling magical energy into them and releasing their True Names.

As the ' ultimate mysteries' and embodiment of the heroes, they are trump cards carried by each to be used at an appropriate time. Noble Phantasms make up part of the existence of Heroic Spirits, the anecdotes about their prowess and weaponry all becoming part of the very ' symbol' of their existence. Enkidu is described more as a ' Noble Phantasm of the gods' than a Heroic Spirit, and Kingprotea is a being whose self can be treated as a Noble Phantasm. Sasaki Kojirou is a case of a Servant without a Noble Phantasm due to his status as a wraith, but his technique, Tsubame Gaeshi, has managed to be on par with Noble Phantasms without the use of magecraft. There are cases where the nature of the Noble Phantasm is not actually a true crystallized mystery, such as Archer's Unlimited Blade Works, which is magecraft that symbolizes him, and Li Shuwen's No Second Strike, which is the quintessence of his martial arts. Gilgamesh claims that the ' children cannot defeat their parents', with each new incarnation simply being a deteriorated imitation that cannot match the original model, but Shirou Emiya claims ' but there is no rule that an imitation cannot defeat the original' while taunting him. As with the progression of Merodach, Gram, and Caliburn, all carrying the ' foundation of the sacred right to select the king', each cycle of transmigration causes the weapon to become weaker. Though differing in appearance, renewed weapons hold similar true natures, concepts for their creation, and souls. Those possessed by Gilgamesh are the true original models, different than those that have been renewed from older Noble Phantasms over the millennia. Those like demonic swords and holy swords were granted names and abilities once such legends begin to flourish in their lands of origination, but those within Gilgamesh's treasury are their forms before they were granted such through myths and legends. It is impossible for myths and legends to start from nothing, so they all have common points acting as the foundations that became the model for the legend. Some abilities solely wielded by Divine Spirits like Sarasvati Meltout and Eightfold Blessing of Amaterasu are called Noble Phantasms, so it is unknown if they also fall into that categorization. Even though it can be considered a paradox, unless Gilgamesh as the original hero possesses them, they cannot be handed down as the Noble Phantasms possessed by the later heroes derived from his legend. They spread throughout the world after his death, eventually becoming Noble Phantasms. They were the greatest treasures of the world collected throughout his lifetime, nameless, splendid weapons that acted as the Noble Phantasms' prototypes (原型, genkei ?) before becoming the objects of faith that act as the foundations for their legends. The Noble Phantasms of all Heroic Spirits are said to have originated from the Gate of Babylon, the treasury of Gilgamesh.

Phantasmic book making