This started as an absurd joke list (and props to you if you recognize the title quote), and I hate relying on any single roll of the dice to swing me a game, but...
Some context, if you will.
Last game of 40k I played was the first in which I tried out the Black Legion's Hand of Darkness. My Lord successfully weathered a Daemon Prince's attacks (brought down to one wound), then popped him on the chin with the Hand to successfully make double his points back (and conveniently rolled a Boon to restore his wounds), then went on to get mired in combat against 3 Termis and 5 CSM, only able to kill one per assault phase max. Still, he did me proud, and had me considering about the viability of the Hand of Darkness as a one-shot killer against nasty monstrosities. I mean, with Spineshiver Blade or MoS, he's high enough Initiative he strikes before a Wraithknight. The only problem is ensuring he gets his 2/3 chance to hit reliably...
So why not, I figured, build a list around ensuring that my Lord gets to swing the Hand of Dark against his opponents, singling out the most threatening single model on the board? At worst, he's going to be using it like a Meltabomb against an Imperial Knight; at best, he'll be one-shotting Princes, Carnifexes, Wraightknights and anything without Eternal Warrior with relative ease. You just have to give him a reliable mechanism and a reliable mechanism for hitting with his swing, for getting to his opponent without getting shot to bits. Oh yeah, and some sort of power weapon would be nice, to keep from getting bogged down against chaff, again, since that's gonna happen (and the HoD isn't a specialist weapon, so a lightning claw is sub-optimal).
For this I turn to my regular wingmen Be'lakor and Fateweaver, who are naturally put off by no longer being the center of attention all the time, but don't mind letting somebody else shine for a little bit. Be'lakor can cast Invisibility on my one-man Deathstar, and Fateweaver can Prescience him--also rerolling essential D6s like a 1 to wound or a vital failed psychic test (to say nothing of making some nice Warp Storms go on). Invisibility should hopefully save him against Imperial Knights to let off a few meltabomb hits, from Daemon Princes trying to reap his tally before he strikes, and enemy shooting.
So we have a Hand of Darkness Back Legion Lord who has to have I6 at least, to strike before Wraithknights. He's in an allied contingent if we want Fatey, and I refuse to take Fatey as a non-Warlord... though any Tzeentchi Daemon or Balestar Sorc would really do, but I like these advantages, so I'm sticking with allied Black Legion. That means no Noise Marine troops. As I see it, we can build this Lord 3 ways:
175 - Lord in Termi armor w/ power sword, Hand of Darkness (replacing his combi-bolter), VotLW, and Mark of Slaanesh. Relatively cheap, unless you also want to take what's left of Ker'ngar along for the ride too. I can also use my Abaddon model for this guy because, hey, Termi with fist thing and sword, and I have a kitbash of the HH Abby mini converted to 40k, anyways.
270 - Lord w/ VotLW, MoN, Palanquin, Hand of Darkness, Skull of Ker'ngar, Spineshiver Blade, and SoC. The one-man deathstar; an immovable rock with T5 W5 I6, Eternal Warrior, Adamantium Will, and a choice between an Instant Death-causing super-attack or bucketloads of AP3 melee attacks. Expensive as hell and slow as a glacier, but anything he touches, dies.
195 - Lord w/ VotLW, SoC, bike, Hand of Darkness, and Spineshiver Blade. Kind of the halfway point between cost and survivability/damage output, but far and away the fastest Lord. Still T5 with a 4++ This guy could join Bikers to add more melta and meltabombs to take out AV14 and 13 more reliably, and most reliably get where he wants to go. The Spineshiver Blade here takes the place of both power sword and MoS on the original Lord (though the cost of the sword is tied into his Termi Armor, there), but gets a bonus +D6 attacks for his troubles if he choses to use the Blade over the Hand. Again, Ker'ngar is an option, but with 3 Wounds rather than 5, I dunno if it's cost-effective... to make the lynchpin of my force that much tougher. Ok, yeah, it probably is, if I don't have to cut off something painful to fit the points into the list. If you want a Marked Juggerlord or something... treat yourself, but it's your points.
As for retinue, you're probably best off with a bucketload of Cultists--they make good fodder for enemy shooting (especially while Invisible), you don't have to buy them VotLW, and their attacks should heap onto the Lord's to help clear out enemy attempts at roadblocks. Honestly, throw enough 3-attack-on-the-charge (plus pistol in shooting pre-charge) cultists at a problem, and you should end up getting a decent number of wounds through. Unless you're bringing the fast Lord, there, in which case Bikers are probably a better bet than Spawn, for the meltabombs. Bikers can also Jink within Be'lakor's Shrouded bubble for a 2+ cover save.
Ew. 2+ cover unit (on bikes) hit only on 6s in shooting and melee, led by an absolute monster of a Melee Lord who can one-shot anything you throw at him (with Prescience and Fateweavers reroll)? That's about as reliable and unkillable as you can get. Unless you throw Lysander at him, with a 3++ invuln and Eternal Warrior, or something.
Ahem. In conclusion, the list. I'll go with Biker Hand of Darkness Lord here, since the synergy with Be'lakor has convinced me over the course of writing this whole diatribe. Also that makes his modus operandi pretty "Wham, bam, thank you ma'am," and the more cheesy one-liners I can fit into this rambling foolishness, the better.
TL;DR: to squeeze this idea into a mere 1500 points, I would bring the following:
300 - Fateweaver
350 - Be'Lakor
45 - 3x Nurgling Bases
45 - 3x Nurgling Bases
150 - 6x Screamers
235 - Lord w/ VotLW, SoC, bike, Hand of Darkness, Skull of Ker'ngar and Spineshiver Blade.
58 - 12x Cultists
140 - 5x Bikers w/ 2x melta, VotLW & Champ w/ meltabombs
175 - Forgefiend w/ 2x HAC
There are some on-the-fly alterations to this list, and some expenditures with spare points. The Forgefiend I threw in for some more anti-Wave Serpent, which will be predominant on the competitive scene, I figure. I added the Screamers for another unit with a 2+ rerollable cover save (when hugging Be'lakor's Shrouding bubble) and access to Armorbane attacks.
I had 15 points to spare after adding Ker'ngar to the Lord, so I opted for a MoT, too, for the 3++ invuln; why not, it's better than another base of Nurglings. It fits with Fatey and the Screamers, to boot. I felt bad about sacrificing Horrors (great Warp Charge batteries) for Nurglings, but managed the squeeze in order to get 5 bikers in there.
If I were running this at 1750, I'd probably bring another Daemon Prince (heavy support) with a Grimoire (or 2 Horror Squads and a Grimoire Tzherald, perhaps, in another force org chart), and if possible a Burning Chariot for the versatile damage output (coupled with that Fateweaver'd Grimoire's defensive boost to make it survivable enough).
So. I realize this is an idea-dense wordspew to pick through, but I welcome your guys' thoughts and opinions on the matter. I imagine
will advocate that I drop into full Unbound mode, since these troops and lack of Grimoire aren't doing more than slowing me down, but I am considering running this list in a 1500 point Battle-Forged tourney (hence my initial 1500 limtation). But I would welcome seeing what somebody would do with this if it were Unbound, and at other points levels.