Q: Although it did not appear in the works, can Caster use a Reality Marble?

A: Unfortunately, Caster cannot use it. But, if it is a magus of her level of excellence, by precisely constructing small magecraft and large magecraft, she can construct "another world" of the same scale, don't you agree? Well, the time and expenses required for that is vast, after all.

Comptiq 2007 Issue 4; Fate Dojo Q&A