Anyone have a good LL write up on Mind Flayers? Without all the AD&D type psionics? IIRC they predate the original Monster Manual. Wondering what would be a good way to simulate the psionic thing without having to resort to points and all the cumbersome stuff......
See page 63 of Mutant Future for the Brain Lasher. All of those monsters work with LL. MF also has an elegant system for psionic style combat. Realms of Crawling Chaos has a good psionic type system as well.
You can also find a description of the mind flayer here: http://carterscartopia.blogspot.ca/2011/02/rocc-psionics-and-mind-flayers.html, but you need Realms of Crawling Chaos to fully use it. Or try the variant here: http://grognardia.blogspot.ca/2009/02/grognards-grimoire-thelidu.html
Have you tried using the Brain Lasher form Mutant Future? You might have to do some conversions to account for the mutations. I would recommend dropping the Ancestral Form mutation. Otherwise, most of the mutations seem to be at-will spell-like effects.