One leech falls on her

Man… I just thought about it, and yeah, Demongo would have been much better here.

It's a prison, full of violent, evil alien-creatures. Maybe Demongo happens across it, finds a bunch of powerful guys already locked up and easy pickings. A nice little essence buffet. Jack and Ashi happen across and Demongo is just squealing like a little demoness, ready for round 2. So instead of Jack running around in that canyon, fighting and avoiding baddies, it's this ship.

Maybe he beats Ashi and uses her to fight Jack? Hell, maybe he beats Jack and Ashi has to defeat them. In the end, hearts still racing, adrenaline still pumping, they just break down and fuck like animals.

Even the scene towards the end where the slugs form multiple guys with different appearances, kind of reminds me of Demongo a bit. Really seems like a missed opportunity. (Unless there's a big plan for Demongo later, of course.)