March 2012 Army List Challenge: Pitch Black

Welcome to the March 2012 Army List Challenge.  If you've not had a go at these before, the idea is to design a themed army list from the codex of your choice to take on a specific challenge.

This month, the theme is pitch black. You are fighting a standard (randomized) mission, but the atmosphere of the planet is thick with smog / tyranid induced fungi spore blooms / volcanic detritus / iron filings from too many necrons being blown to smithereens (delete as appropriate).  Every time any unit shoots, they must roll a 2d6 to determine the range they can see to (a little bit like an extreme night fighting scenario).  Spot lights and so forth don't help. Nothing pierces the gloom. Weapons that do not require line of sight are unaffected ("guess" weapons).

So, will you take an all assault army? Will you rely on guess weapons?  Or do you have a different tactic all together?  (extra kudos for the latter!)

Rules

(1) Design a 1500 points army list from any codex to take on this challenge.

(2) Post your army lists as a comment to this posting and suggest why the army list is effective and themed to the scenario.
(3) Entries close at 01:00 GMT on Mar 14th.

(4) On that same day, I'll open a poll for Warpstone Flux readers to judge which army list they consider to be the "most effective army list that also best articulates the theme" (whatever readers interpret that to mean) out of all entrants.

(5) The winner will be tallied and announced on Mar 21st (and entered in to the hall of fame!).

(6) One entry per person please.

Remember that there are no prizes for these contests, beyond kudos, honour and entry in to the hall of fame.

Good Luck!