Inside the Tentacle Cave manga volume 2 features story by Umetane and art by Abi.

Consuming adventurers and bending female mages to its will, the Black Ooze grows in both power and hunger. Frederica and Fiana, warped by demonic lust, hatch a plan to lure fresh bodies into the mines—and they’re on the verge of success! Is there any hope of escape for Satia and the other victims?!