Not wrong, the Dark Souls vibe is more coincidental (it unfortunately influences damn near everything I make at this point) while the setting of BLAME! definitely played a part in influencing Vast.
Never heard of The Night Land, but looking into it I'm intrigued.
I'd personally recommend "The Night Land" retelling by James Stoddard, which updates the archaic prose/characterization of the original and really lets the "Far future Earth where the sun has gone out and horrors swarm around the final fortress cities of humanity" setting shine.
