People keep saying that, but actually the whole Nasuverse hangs together really well and we get references to new mechanics and events ten years and several works in advance. Try playing Melty Blood after the first arc of Grand Order, for example....
Well, it is in fact canon, but there's an explanation consistent with the rule you've already given --
Dunno why it calls it a Reality Marble but whatever. Anyway, it's fine, you can unify them with only a little bit of Nasubabble (and a bit more math babble). Just note that "space" is a property of the "World", and that you do have your own World to work with. The area inside the ego boundary - aka your human body - is a place where your inner World and Gaia's World intersect, so it's kind of like a wormhole connecting two universes. But aside from that intersection, it doesn't really make sense to use one universe's coordinates for a location in another - like, trying to give an Earth-based latitude and longitude for a place on Mars.
So you can "address" locations in your body by relating them to your own personal World, which of course is at rest relative to itself. But that only works for locations "inside you" - that coordinate system just doesn't cover anything outside your body. So Kiritsugu's spell is merely difficult, while Araya's mobile ward that targeted an area several meters out from his body is bullshit Origin-enabled "one step below Sorcery."
Well, there's still the weird bit that strictly speaking your arms are moving relative to your center of mass, but I guess you can say that it's like, no matter how a mountain changes, the latitude and longitude of that mountain won't move?
Well, anyway, that's probably way too complicated to ever put in the story but it's a cool thing to work out.
At this point I'm attached to using "Bounded Field" = "relative to The World" because that mostly matches how it's used everywhere else in the setting, both in detail and especially in theme.
Well, it is in fact canon, but there's an explanation consistent with the rule you've already given --
Fate/Zero Book 2 said:The ability to separate the passage of time inside a designated space from the flow of time in the outside world—in some ways,
Time Manipulation could be regarded as a type of Reality Marble. Although classified as greater magecraft, it was definitely not unreplicatable magic. Compared to Time Modification, which could reverse cause and effect, changing the past, this was merely magecraft of Time Adjustment which could stagnate time passed and accelerate time to come; it was not magecraft of extraordinary difficulty. The only consideration was the size of the bounded
field and the scope of time that needed manipulation.
...
A method that limited the bounded field's scope within the practitioner's body made it easier to establish a Reality Marble. Although it was impossible to completely isolate the flesh from the outside world, it could minimize the effect of the outside world on the body. Within this minimal bounded field, he could manipulate time, a few seconds at a time. This was the magecraft that Emiya Kiritsugu created—Innate Time Control.
Dunno why it calls it a Reality Marble but whatever. Anyway, it's fine, you can unify them with only a little bit of Nasubabble (and a bit more math babble). Just note that "space" is a property of the "World", and that you do have your own World to work with. The area inside the ego boundary - aka your human body - is a place where your inner World and Gaia's World intersect, so it's kind of like a wormhole connecting two universes. But aside from that intersection, it doesn't really make sense to use one universe's coordinates for a location in another - like, trying to give an Earth-based latitude and longitude for a place on Mars.
So you can "address" locations in your body by relating them to your own personal World, which of course is at rest relative to itself. But that only works for locations "inside you" - that coordinate system just doesn't cover anything outside your body. So Kiritsugu's spell is merely difficult, while Araya's mobile ward that targeted an area several meters out from his body is bullshit Origin-enabled "one step below Sorcery."
Well, there's still the weird bit that strictly speaking your arms are moving relative to your center of mass, but I guess you can say that it's like, no matter how a mountain changes, the latitude and longitude of that mountain won't move?
Well, anyway, that's probably way too complicated to ever put in the story but it's a cool thing to work out.