Welcome to Librarium Online!
3 Tomb Spyders
Lord (Dbody, Wsythe) 140
9 Heavy destroyers
What do you think? Anyone got any more cheesy armies?
too bad that c'tans can only be used in 1500 point games and up
not enough troops.... you need to be able to hold objectives...
On topic: As mentioned before, you would need more troops for objective purposes. But you could always try to overwhelm your opponent and claim victory by just killing his army. The only problem with the first list is, your Phase out is too low and that encourage people to ignore the C'tan. As for the second list, that might have a change by sheer fire power. You could kill all his troops, while evading the rest of it.
The c'tan can be used in any point games. I know the phase out is low in 1000pt list but the scarabs can tie up opponents to stop the warriors getting shot and once the NB and his friends get to the enemy their won't be much left to attack you with. The army REALLY is good. The only trouble with it is deepstriking units, but keep the warriors close behind the tomb spyders and they should be pretty safe. However, vanguard charging from deepstrike are a HUGE problem. But its fun overall.
As for 1850, as you can see, its along the lines of mature stilton.
I like the second list. I've used a similar list in the past and it served me well. I would add another unit of warriors and drop a unit of Heavy Destroyers.
My main concern for your first list is the small Scarab units means a lot of kill points for your opponent for Anniliation scenarios. Your only damage comes from the Nightbringer and 20 warriors, so you'll have to come up with at least 3 kill points by the end of the game to tie him and hope he doesn't wipe out your NB early.