Honestly, Devin should have expected this, knowing Valdis. Even if he couldn't pin down exactly why she would want to replicate the bit of experimental linguistic magic, he ought to have guessed she would want to. All the same, he is not especially thrilled by the idea. For one thing, she doesn't have a firm grasp of Enochian - or at least not this version - and he'd like to keep it that way. This one skill he has continues to be startlingly effective against her (and more importantly, against the Void). In fairness to Valdis, this is also likely why she has not asked him to teach her, and has only made minimal observation of what he can do with it beyond 'imprison me in a room'. Strictly speaking, he might be able to show her how to make a similar ward without teaching the mechanics of it, but that was hardly reducing his concerns.

And for another thing, Devin doesn't know if the Void will be able to learn its way around the magic with more and more direct exposure to it. Almost all Enochian wards or other spellwork have loopholes - if the language was a woven tapestry, there was nearly always a way to worm between threads. Or else, to barrel straight through them. But he was jumping to all the possible conclusions without actually knowing what she was after, so Devin gently put down the book he was working on. His full attention was needed here.

"That was not meant to be supernatural Ambien," he remarked dryly, gesturing to the torn bit of cloth. "What manner of replication are you after? Simple copies or something else?"