Jack Barricade's Clues

They're not exact counterparts. Actually, that's why I brought up the "Female Grandmaster Mage" point - Lukan describes Delgrund as being the Grandmaster in his time, and Delgrund was male. These are not the same people, nor are they mirror counterparts.

and Chameleonic hit the nail on the head with that, it's exactly my point. It's not that he says he's being carried by a stone monster that's the main part, it's how he describes being carried, which is in a manner that makes it completely impossible for the monster in question to be guardians.

We seem to know that Crimsonheart is the Twisted Masters' goal. But why do they need him? Could he be the key to operating the giant statue, or are they trying to get the Indigo Phoenix? What's the motive here?

maybe crimsonheart's tomb is the way to the Old Sapp' Village?
aka, like the FMA anime- when a huge dead city is being discovered under a church..

Or maybe there's something inside the tomb that the Versalians need.