Post-EW MSQ Spoilers!
Just realising now that we've been, essentially, using the Contramemoria since ARR. Or something similar to it.
White Auracite and the Ascians. Not identical, but extremely similar. Prevent a thing from returning by rendering it immutably static. Might be some basic-ass lore I'm on here, but that's very interesting to me. Might be forgetting, since they don't end up in the crystal, but it kind of acts as a focus for the Light, but still interesting.