A look into the Iyanden codex supplement and some of the army builds you might be seeing or wanting to use.
Wraithguard with D-Scythes
The first of these is the Wraithguard with D-Scythes and a spiritseer. Spiritseers can be taken as a council called a shadowcouncil, so 1-5 per HQ slot. The importance of this is that the Runes of Battle primaris power for Iyanden Spiritseers is Voice of Twilight.
Voice of Twilight
Wraigthguard, Wraithknights, Wraightblades, and Wraithlords within 12" get battlefocus.
Now this means that Wraithguard in a Waveserpent can move 6", deploy 6", run d6, and flame with their D-Scythes 8" template. This is a S4 AP2 template with distort. Instant death and always wounds on a 6 or penetrates armour on a 6.
Dont forget Vectored Engines for wave serpents, so that you can turn your wave serpent back around so you do not lose it. The addition of a Farseer with doom really shows off the power of this, as you can re-roll to wound or penetrate with your D-Scythes. Just wow.
Spiritseers and Wraithknights
The next build is with a Spiritseers and Wraithknights. The goal here is to take enough spiritseers to get the first power on the runes of battle, Destructor/Renewer. The power is one friendly model within 18" regains a lost wound. Powerful when you are talking Wraithlords and Wraithknights.
So multiple Spiritseers with Renewer, along with one that carries the Wraithforge Stone can get very powerful. This stone makes one Wraithlord or Wraithknight within 6" regain a lost wound on a 3+ during the movement phase.
This makes an already powerful unit very strong, and the need to be able to drop in a single round becomes very important, and very difficult.