D'rek Question + Cheesy Ending

If I'm not wrong, we never see or hear D'rek until the end of book 10 which is odd since she's part of the endgame. Is there lore reasons for this? I've read a few of the ICE books too and I don't remember.

However,watching Dune 2 reminded me that giant worms are cool so picture this:

The Glass desert is just a regular sand desert, we trudge through miserably for half of book 10. Seeing that they might not make it in time, the D'rek priest (forgot his name) finally does something useful and calls his god (hopefully killing himself), which manifests a bunch of huge worms that carry the Bonehunters towards the spire. While Fokrul and co. are being defeated, Tavore and Fiddler worm ride past everyone to Kaminsod's body, as the giant worm protects them, she stabs TCG with the otataral sword, killing him, Cotillion shows up and shadow dances all the enemy NPC's, Shadowthrone finally shows up an Tavore kneels finally revealing she was a Talon the whole time.

Cinema.