Well, that’s a little cryptic.
Cryptic Spires is a card that requires you to make a choice during deck construction. While we have some precedence for this with Conspiracy, this is the first time that multiple cards in the deck with the same name could have different choices made for them. Usually, the choice is made before the event begins and does not change, but in events using Continuous Construction rules, that choice may be changed between games.
How that choice is conveyed is up to the player, as long as the following two requirements are met:
* The choice is clear and unambiguous. The easiest way to do this is to mark the card directly, but if the choice has changed, those markings need to make the current selection obvious.
* The deck remains visibly unmarked. Using a small slip of paper is an acceptable option provided it does not notably impact thickness within the sleeve.
As the primary use of these cards will be in regular REL limited events (such as the Double Masters 2 prerelease) there’s no need to be heavy-handed when a player makes an unintentional error. Work with them to fix the issue so that it doesn’t happen again. In the unlikely event of these cards being used in a Competitive REL event, the choices made must be marked on both the decklist and the card.