[[You can still make symmetrical patterns with 7, you just need one in the middle, right? And considering all the ones Bakura had seen (and even the ones he hadn't) were symmetrical in and of themselves...

He nods]]

Un, a bit. The ones I've seen, their specific abilities are pretty well known, just from seeing them in action, it's the history of why they were made and how they work and things like that that are still the big mysteries.