What will the “third book” of Braveland be like?

Hexes aren't the best solution for multi-tile bosses, especially if there's a large army nearby. But it's worth considering.

If there are no obstacles on the battlefield, then it could work, in my opinion. But that's only if there are no obstacles.
Although, it can work even with them... The boss doesn't necessarily have to move; just remember KB in this regard.