Taken from the Encloypedia/click me
(
"Marble Phantasm
Imagination Realization. As the name suggests, it is the ability to manifest anything you can imagine. I really wish I could do this.
It is the ability possessed by elementals, which are the sense of touch of the natural world. By connecting their will directly to the world, they are able to transfigure the world into whatever environment they imagine.
Of course, the level of manifestation varies depending on the scale of the elemental, and it goes without saying that only nature can be transfigured—things that exist independently of nature are immune.
In Tsukihime, Arcueid eliminated Roa by using marble phantasm to turn the layers of the atmosphere in the hallway into a vacuum, like a carving knife slicing up a daikon radish.
Though she could not affect Roa himself, it was impossible for him to avoid the finely sliced atmosphere, and he was reduced to nothing but ankles. (The gap above the floor was the result of a deficiency in Arcueid's imagination.)
Also, in the world of Tsukihime spiritual realms are not alternate dimensions, but rather exist within the world itself. Things like legendary lands and countries of eternal spring are the products of the imagination of whatever elemental rules over them. Consequently, it is possible for humans to wander into them by accident.
The castle in the mountains that Arcueid calls home is actually a product of her marble phantasm."
"
Reality Marble
Intrinsic Field.
Originally referred to the alien common sense possessed by the beings called devils, but now also includes the unique boundary fields possessed by many people.
A subset of marble phantasm, it erodes reality and gives form to the user's imagined world.|"
"
Hippogriff
Otherworldly Phantasmal Horse. The third cheat Noble Phantasm used by Rider of "Black," Astolfo. There are cases when a Griffin, a Monstrous Beast, reproduces with a mare, which would normally be its food. What's born as a result from this is the Monstrous Beast known as a Hippogriff, which has the upper body of an eagle and the lower body of a horse.
However, it is an impossible creature which normally should not exist. This is because it should be impossible for a child to be born between a Griffon and a horse, which are predator and prey. The Hippogriff existed only as a hypothetical and philosophical symbol. A Hipppogriff appears in the story of "Orlando Furioso" (The Frenzy of Roland), where Astolfo and his comrades also appear. This story includes the theme of "The Hippogriff makes an appearance here, so no matter how strange it may seem, there is nothing that is truly impossible." In "Orlando Furioso," Astolfo even goes to the moon in order to save Roland.
The Hippogriff that Astolfo rides is a "Phantasmal Beast" in the true sense, since its very existence is uncertain. As a result, when it is released as a Noble Phantasm, the Hippogriff can jump over to a different dimension, though only for an instant.
That dimension is the home of the Phantasmal Species, where only beings that are purely non-physical souls can go to. It is the Reverse Side of the World, which the Hippogriff, when summoned as a Noble Phantasm."
)
I went through the encloypedia entries. Marble phantasm, and reality marble then compared it to Astolfo's NP descreption. This is what i found.
" in the world of Tsukihime spiritual realms are not alternate dimensions, but rather exist within the world itself. Things like legendary lands and countries of eternal spring are the products of the imagination of whatever elemental rules over them. Consequently, it is possible for humans to wander into them by accident.
The castle in the mountains that Arcueid calls home is actually a product of her marble phantasm."
"A reality marble is a subset of marble phantasm, it erodes reality and gives form to the user's imagined world."
"The Hippogriff that Astolfo rides is a "Phantasmal Beast" in the true sense, since its very existence is uncertain. As a result, when it is released as a Noble Phantasm, the Hippogriff can jump over to a different dimension, though only for an instant.
That dimension is the home of the Phantasmal Species, where only beings that are purely non-physical souls can go to. It is the Reverse Side of the World, which the Hippogriff, when summoned as a Noble Phantasm"
There is a clear difference here. Marble phantasms produce realities that can share the same world. realitiy marbles are a subset power of Marble phantasms. HOWEVER! Astolfo's noble phantasm description clearly stats the reverse side of the world is separated entirely. It differs from the above 2 significantly. Therefore we can rule out them being reality marbles, even if accepted this means that nasuverse earth is larger perhaps way larger than normal as there is an uncountable addtional landmasses.
This didn't edit the way i wanted it too...
I am going to bed though so i'll have to respond a lot later tomorrow lol.
