Giant Octopus! (or at least it's tentacles anyway)

Fujimaru Ritsuka and the group looked around the room. It was around the same size as the first floor, with the spiraling stairs continuing at the front and incredibly deep and thick floors.

While everything at the first level was limestone, everything at the second level was wood. In fact, a giant tall wooden mast with a badly tattered flag stood broken in half near the left of the stairs, the upper half having fallen and getting stopped by the walls of the roof so that it didn't fully topple over.

They just shoved a shipwreck in the tower and called it a level? Fujimaru had seen worse architecture, remembering a particular Halloween incident featuring a certain dragon girl and her robot lookalike that had him run through an European castle... With an inverted pyramid stuck on top... And a japanese castle placed at the very top.

"There's something moving underneath the floor!" Mash's scream shoved him out of his remembrance. He looked down through the holes in the broken planks to see a gigantic orange eye moving below before giant thick curling tentacles with suckers smashed through the floorboards, lashing out at the group as they leapt to avoid the attacks.

"Watch out for the suckers! They'll stick on to you!" Fujimaru warned as his servants leapt into action, again forcing him to put logic over lust as he saw their now enlarged tits and asses wobbling as they leapt in the air.

For a good few minutes it was a tussle. The tentacles seemed to move quickly, avoiding the hits and slashes of the weapons while the servants were also acrobatic, leaping and twisting midair to avoid the smacks of the tentacles.

The thrashing of the giant octopus underneath shook the floor like an earthquake, causing the normally ducking and leaping Fujimaru to eventually lose his balance, falling sideways before a quick tentacle grabbed him from the air.

"Master!" His servants were distracted, stopping their constant movement, which allowed the other tentacles to grab them too.

"Urgh!" Artoria gasped in discomfort along with the other girls as the tentacles bound them tightly, coiling around and squeezing their increasingly voluptuous bodies.

"These suckers are... Effective!" Boudica tried to stifle a moan as the suckers latched on to them, providing suction on large patches of their bodies and erogenous zones.