["That Milla woman." He can't help but find that to be a little amusing, although...]

It does and it doesn't. [How...vague. But he'll do his best to explain.] Spirits do need to be present for the use of general artes, because they are called upon per use of an arte. But the Chromatus is different, as it has already been imprinted on us by the spirit. We only need a specific physical conduit to activate it.

[...]

I've managed to retrieve that conduit here, but it has no effect in this place.