I went back and redid what I had for the ceiling, and I'm much happier with it now although it does stick out a little less. i think part of the issue i had before was that there was too much of the ceiling visible, particularly compared to the floor.

thats the main version.
i also have another version here, which exists mostly to mine for tiles.

and if anyone is curious, here's the whole tileset thus far;

i haven't tiled the pillar yet, not sure what im doing about that just yet.
Take notice, however, that there is stark contrast between the sharp detail of the foreground cliff's rocks and the blurred transition from the foreground to black.
i see what you mean, i'll look into it. i might end up redoing or altering the foreground cliff tiles anyway.
However, I would lose the pillar or heavily edit it.
yeah, i'm not very happy with it. i'm not sure what i'm going to do with it yet, i might just remove it and edit it and place it somewhere else in the game. either that, or i'll start imbuing some more greco-roman ruins into the cave and then edit the pillar after that to resemble those more.
thanks for the comments and critiques everyone!