The Realm/Elemental banners contain all relics up to a certain cut off point, so they do have Sync's in the pool but the pool of Syncs is low-ish, and there is a large amount of relics mucking up the chances of pulling a sync. The banners do get updated about every 6 months, and we're a month or so away from the next refresh.
And on the topic of banners, got another hit on the Magicite tickets: Rem AASB! Got her Sync from fest, and from what I've been seeing, she rips Diabolos a new one. Now I just need a holy magic csb....
Edit: Oh yeah. New Book missions centered around Cardia dungeons. Up to 4 free tickets. Time to stop ignoring them I guess.