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What Ive been noticing at our hobby center is that nobody really ever uses either of the C'tan in their army. Though I've only seen it twice, it still seems to little for such a powerful character.
But I DO understand that it uses up ALOT of points and can cause phase out quicker if it dies.
Other than that why dont I see many people using it? Expecially in some 2500pt+ battles ive seen.
C'tan are too many points to use at low levels and at large games they have the tendency to attract a hell of a lot of fire.
The Nightbinger is the easiest to use at larger points, just plonk him down and ket him kill stuff.
The Deciever is a lot tricker (would you expect any less?), he is at his most powerful in really large games, where a combo of him and pariahs can take anything (also pinning fearless units is fun). The again, he also works in smaller games that the nightbringer because he isn't a simple CC monster, his abilities aid the army in many ways (like a monolith does to be honest).
IMO you'd be a fool not to use C'tan in a 2500 pts army, when you have that sort of point limit PO is barely a concern.
I found the most fun in using my nightbringer in a low point battle. I went with wraiths, a Dlord escort, and a nightbringer in what was something like a 1,150 point game. My phase out was at six. Now most people would surmise correctly that the list is very vulnerable. I found that the excitement of smashing things with my god, then during their assault blow the guardsmen away, then re-assault with my god, and then blow all their squads away (sometimes even off the board) was something I would not give up for any thing else in the army list. The nighty must have killed 3 guardsmen through overheating plasma alone and absorbed more melta, plasma, rocket, and hunter-seeker missiles that I could count. Of course I lost 4 wounds, but he lived throughout the game and only 7 warriors where lost from a deadly battlecannon blast and an insane lasgun shot. (all the wraiths ended up dead, but that was due to a bad move, some lucky powerfist hits, and bad WBB rolls (I think I missed all but 1.)
Would I suggest always taking a c'tan, absolutely not, I happen to also have a soft spot for pariahs.... but that is mainly because everybody seems to dislike them (no matter what, I'm using 360 points).
"When a necron gets hit with a weapon more than double its toughness it is hit so hard that it goes into "negative damage" and does less damage than it actually would if it hit him with less force!" Quote from azimaith on Warseer, contemplating how much GW will Nerf the WBB rules.
Yep, I also have thought about bringing him (nightbringer)in a 1500 point game. I keep running my Marines into three wraithlords and an Avatar....I figured god on god, I may be able to take those chumps down....especially with a tomb spider wall to get there. Never used deciever....I have one but, it took me long enough to paint 2500 points with a C'tan....I didn't fell like slopping paint onto another 300 point god.