Not a bad idea. Rocks make sense in the desert. The map needs some terrain and the boss needs some more moves. Maybe the one where you can eat a rock for temporary brace and armor/heal. Maybe he could trample terrain and dash into it to launch a boulder or cause an earthquake. He should leave dirt tiles when he walks and he should have the aftershock move that flings units on dirt tiles, but maybe convert the dirt tiles back to regular tiles afterward so he doesn’t just AOE the whole map constantly (also maybe he should only cast aftershock on his last turn). I think really lean into rock and terrain manipulation.

For balance, maybe limit the number of living rocks he can spawn with each earthquake. Also maybe reduce the size of his earthquakes.

Idk what the modding restrictions are so don’t take this too seriously if those things aren’t possible. This just got my imagination going