Is it possible to access the Dark Havoc base having beaten the game? There's an NPC in Letovi that implies it is, but I can't find it anywhere.
You can access the area after completing Chapter 6 just before you meet Alyssa in Letovi and enter Camaris which can be accessed through the crossroads where you first encounter Dark Havoc. It's easier to wait until Chapter 8 as you can head there through Alverona and won't have to go through Greywind to get there.