This assumes that the Mind Flayers are bound by our reality and need to worry about such things rather than being the Cthulhu-esque abominations that they are in the versions I find to be the most interesting.This sounds really cool until my brain thinks about it for a little bit. Like, if y'all put out the sun, entire ecosystems are gonna go to crap fast and THEN whose brains you gonna be eatin'?
(Although the ones in the Astromundi Cluster doing this is incredibly dumb given their origin in that boxed set - but since that origin is also incredibly dumb IMO I'm glad that everyone has agreed to forget it ever existed).