So this week my players are heading down to the deepest foundations of a Chint-on palatial hive in search of the...

So this week my players are heading down to the deepest foundations of a Chint-on palatial hive in search of the reincarnated personage of an NPC's tomb-robbing wife.

I'm looking for ideas, flashes of inspiration etc. to help fill this thing out more fully. What I've got so far is this:

The central palace sorts the queen's eggs into four castes - Warriors, Viziers, Workers and "rejects" aka Slaves. The Slaves were overseen by the Duchess (an ergatoid 'false' queen) who rebelled, and now in modern times there are only three castes. Meanwhile down here there are the remnants of how that war was "won" - cordyceps-infected chint-on slaves.

In addition we have Golden Wormlings, chint-on berserkers who went mad with love for the queen and got chucked down here to kill as many monsters as possible, big ol' moths instead of bats, a baital, a giant centipede-cheshire-cat-smaug thing called a Shehezar and... well that's where you all come in.

The basic idea is the green corridors are main throroughfares but the walls are "porous" - they can clamber through abandoned buildings ad nauseum to get to the other side of things rather than following the roads. As for what they find in there, who knows.

What other factions, monsters, magic items and concepts could fit right at home here, among the ink-black dark of the Deepest Palace?

(I will make a more official PDF or something of these things post-game)