As the Japanese name implies (空想具現化 Kuusou Gugenka), Marble Phantasm is the ability to materialize a phantasm, a vision.

It is the ability of an Elemental or True Ancestor to connect their will to nature, to interfere on probabilities, and to transfigure the surrounding world at will according to their vision of the world. As the user is a part of nature, he or she can change the world as desired, but in the end, what an elemental can act on is only something within the scope of nature. The capacity of the actualization is proportional to the scale of the elemental. A transformation independent from nature (such as transforming a human) cannot be realized, unless done indirectly. While on the other hand animals, who are part of nature, can be controlled by the Elemental.

In the settings of Tsukihime, the spiritual realm isn't a world separated from the real world, but localized regions thought of by the elemental that creates them; hence it is possible for a human to stray into it.

In the story, when Arcueid uses Marble Phantasm on Roa, she turns layers of the atmosphere in the corridor into a vacuum that cut him like a knife would a radish. Although Roa himself was not affected, there was no way to avoid being chopped in pieces by the atmosphere, and Roa only narrowly managed to remain as just his ankles - Arcueid's imagination didn't go as far as having the floor dislocate. When not restricted, Arcueid can create a village in the mountains. But where humans have made changes, it will take more time to first break it down.

Millennium Castle BrunestudEdit

The Millennium Castle Brunestud (千年城ブリュンスタッド, sennenjou buryunsutaddo^?), originally the lair from Crimson Moon Brunestud and a piece of his Reality Marble, is currently reproduced by Arcueid's use of Marble Phantasm. The original master of Millennium Castle has already been annihilated, but since then, those True Ancestors that were able to form it, through their Marble Phantasm ability, were given the title of Brunestud and treated as royalty. True Ancestors, beings that have no concept of social stratification, call Arcueid the princess for this reason. It is existing in the location closest to the moon, not topographically, but where the world receives the most influence of the moon. It is the castle Arcueid sealed herself into, depicted as chaining herself to the throne, after getting tricked into drinking blood by Roa and killing other True Ancestors. Even without Arcueid around, the castle is still seemingly in existence, but without "life". To the True Ancestors, the castle was probably their absolute protection.

SourceEdit

Based on the Tsukihime Dokuhon PlusPeriod dictionary entry (p.178) and the dictionary resource at Jonnobi .

The English name comes from a mathematical metaphor. When drawing a marble in a bag of black marbles with a 1% chance of drawing the one white marble, Marble Phantasm is the ability to raise that chance to 100% and definitely pick the white one amongst all the black ones; this remains within the laws of the world.

For comparison purpose, following a similar analogy, a Reality Marble would be, on the other hand, the ability to turn all the marbles into white ones; this is something the world wouldn't naturally allow. While this can be considered to be more efficient, this is, however, the only one effect such a Reality Marble could specialize in.

Tsukihime
Main works
Tsukihime • Tsukihime anime • Tsukihime PLUS-DISC • Kagetsu Tohya • Melty Blood • Melty Blood Re-ACT • Melty Blood Act Cadenza • Melty Blood Actress Again
Terms
Age of Gods • Ahnenerbe • Church • Dead Apostle • Demons • Demon Hunter Organization • Familiar • Magecraft • Marble Phantasm • Reality Marble • Psychic • Tohno • True Ancestor • Vampire

Magecraft
Concepts
Bounded Field • Conceptual Weapon • Gradation Air • Magic • (Second Magic • Third Magic) • Magical Spells • Marble Phantasm • Mystic Code • Mystic Eyes • Psychic • Reality Marble
Creatures
Demons • Familiar • Homunculus • Humans • Phantasmal Species • Spirits • Vampire
Holy Grail War
Command Spells • Great Grail • Heroic Spirit • Holy Grail • Master • Noble Phantasm • Servant • Servant classes • Servant Parameters
Mage's Association
Barthomeloi Lorelei • Magician • Magus • Sealing Designation
Terms
Akasha • Chants and Incantations • Elements • Gaia • Magic Circuit • Prana • Soul • Thaumaturgical Crest