Please explain the Wave Serpent to me

Aschen wrote:

the whole 'ignoring cover' thing doesnt seem that good until you are hiding behind ruins.  You get a 3+ while your opponent gets nothing...its kind of a big deal

Yup, to me 7th edition competitiveness has a lot to do with obtaining Ignore Cover.

And yes sadly the Dark Eldar have decided, not like the Craftworld pansies, not to use ultra effective technology. They rather scare the opponent into cover, feast on their anguish and only slowly killing them off.
Giving the enemy to chance to kill the Dark Eldar, only to feed their false hopes of saviour.
The rush of being killed is almost sought for by the Dark Eldar, they like "walking the plank" and jump back on the ship just before the ocean is going to swallow them.
And if they did get killed, their bodies would be restored anyway by the Heamonculi tapping life essence of the hundreds of slaves each owns.

The Eldar crap their pants so hard that they want to use technology that's always super-efficient, securing the kill. Dark Eldar prefer giving the enemy the chance to survive and produce more tasty emotions, for the Dark Kin to feast upon!

Well to me the rules really reflect fluff on the Eldar stuff. They are superior and the Dark Eldar are just more debased and making the fight fair just because they enjoy it more that way.

Pressing that 'win-button' just wasn't enough of a thrill for the pleasure cults

I take it your using an allied hq aswell? I've had great success with basic guardians buffed by an attached farseer, give them doom/ twin link and or shriek and that should be a marine squad dead. (Hint: add a weapon platform for the guardians to tank shots back at them with it's 3+) also if your happy with your AT choices star cannons are nasty, a dissy ravager would be better but your choice

use an archon with a blaster and a wwp dropping in a squad of 5 wraithguard! better than trueborn at that point, a dead MC or vehicle, and a scary wall of undeath wrapping your HQ.