Get a cheap copy of the necron army book of ebay, the 'old ones'vs c'tan starvampire war is well written, even justifies the creation of the eldar wraithguard, hints at the imperial machine god revered by the adeptus mechanicus on mars at being a c'tan-the void dragon, explains the blackstone fortresses in the gothic war(talismans of vaul), how the denizens of the warp became fell daemons 'harvesters'(psychic backlash from the energies that the old ones had released) and even the origins of the krorks(orks-used as area denial weapons) and eldar (cultivated for their psychic prowess in assisting the old ones).
Yes they knicked 'old ones' from HP Lovecraft....
On the tabletop, i love the flayed ones for their deep strike, not to mention painting wet torn hides draped over a mechanical skeleton is fun and the 'we'll be back', regeneration roll of necron warriors, although the monolith being an uber-tank with portal et al, always seems to attract too much firepower, regardless of its necrodermis or whatever its called(although it mocks eldar/dark eldar brightlances/darklances)





