With the heartstone, we've seen that the crystals of Hoxxes actively fight back. Perhaps there is some kind of greater, and as yet unknown intelligence within them.
A future season idea would see crystals infused with intelligence taking more mobile forms. Everything from small and fast attackers to boss fights against crystal behemoths with lasers and dropping rocks like in the heartstone fight, but more mobile and aggressive.
To counter act these boss fights, the dwarves get temporarily powered up exoarmor suits, delivered by drop pods, to jump into.
That's my idea anyway.
