help for level 13

[Cktulica]

hi i'm down at the last level of the dungeon but I can't get the door open.

I figure I still need something but no idea what

also there is one container (a round circle-ish pedestal) that I can't open (i think clipping issue)

might that have what I need? and if so how can I get it.

[Sosseres]

You need to talk to the ghosts. To do this you need to know their language. You can learn that as part of the main quest when you stop the machine that animates the dead.