This isn't point efficient at all, but it's pretty good at beating other deathstars.
5 lords with 2+/3++, warscythes, mindshackle scarabs, a cryptek with chronometron, and a character or two (or three with zahndrekh), then stealing a warrior's ghost ark.
Also 6 wraith with particle casters and whip coils and 0-2 destroyer lords with 2+ and mindshackle scarabs. This is much more point efficient, but has a lower top potential.
Let me explain, death cult assassins are the most point efficient close combat unit in the game. However, their top potential is much lower than a unit of paladins, death company, and many other units, because of how many you can take per squad.
The lord shackle court has a much higher potential than wraith, but you'll pay a hefty premium for it.