UK GT 1850 - with Eldar allies

First up - credit to Muskilla, who's battle reps I've been following with interest as I too like to play competitively but use a non-meta list, so his reps have inspired this build, though with a bit of variation

The Dealer - Duke Siliscus 150 (Warlord)
The Definetly -
8 wyches with haywires, hekatrix with venom blade raider nightshields aethersails 186
8 wyches with haywires, hekatrix with venom blade raider nightshields aethersails 186
8 wyches with haywires, hekatrix with venom blade raider nightshields aethersails 186
8 wyches with haywires, hekatrix with venom blade raider nightshields aethersails 186
The Deathracers -
9 x Reavers with x 3 heat lances 234
9 x Reavers with x 3 heat lances 234
The Destroyer -
Ravager, nightshields, aethersails 120
Allies
The Doom
Farseer, Doom Runes of Warding 95
The Dumb
5 Dire avengers 60
The Dumber
Wave Serpent, star engines twin-linked shuriken cannons 115

That comes to 1752 and I really don't know what to take for the last 98 pts. I want to stay away from including any kabalites in the army due to Siliscus having to join them, and I keep looking at eldar combat specialists which are fail. Could buff up the farseer but think thats a bit crap. Could also include my succubus for a bit more CC punch

here's a question: are star engines now obselete since skimmers flat out in the shooting phase or do they still add 12" to your flat-out, therefore moving 30" in the shooting phase

One thing to make clear - I totally hate it when opponents use psychic powers against me so I will be using a Farseer someway or another. In a wave serpent may not be the best and I realise that but I do want one in some shape or form

Star Engines still work, they just don't contribute to tank shocking at all - any movement in the shooting phase is non-shockable.

Your troop allies are pretty weak. Back in 5th you could have used a falcon to plop them into and hold objectives, but a waveserpent is just going to crash and burn. In my experience, I've had good luck with a unit of 6x Jetbikes, including 2x cannons and a warlock with a spear. You can give him whatever psychic abilities you want, but likely embolden will help keep your guardians on objectives for the best use. They're great for tank harassment overalll, and you'll get more use out of them than your over-priced dire avengers.

Also, take a spirit stone and invest in a fortune, and give that farseer a spear. You can pair them with wyches, and both take shots at anything close to the wych squad as well as fortune+doom the originally accompanied squad and their target. 4++ close combat invul saves will save a lot of wyches...

I used to play eldar, back in the day (which was what? 5 years ago?). The trouble with eldar is that as DE allies they have exactly the same weaknesses as the rest of you're army, only worse. In response to this your Eldar allies should each only be included if they can do something NO Dark Eldar unit can do, as odds are the DE can do it better and for cheap. With the list you're running that basically comes down to:

• Farseers, for obvious psychic reasons.
  
• Rangers, who can do what no DE unit can, hold objectives.
  
• Guardian Jetbikes. These can run with your Reavers and cap objectives.
  
• Scorpions. With the recent buff to Infiltrate and their ALMIGHTY 3+ SAVES WOOHOO! (yes, it's that bad to be an eldar player) they can set up out of site a handy 12" from the enemy. They can't charge, but a unit of 6-10 is a cheap assault unit that presents YET ANOTHER turn 2 threat for less than your raider-wych squads. I've been running some recently, and they rock.
  
• Dark Reapers. Do you play eldar? If so barrage-sniping with a tempest launcher/crack shot exarch is pretty sweet. If not, it's still awesome, but expect a steep learning curve, as these are painfully difficult to use, but worth it if you like the look on an opponent's face as a single model wipes out an entire squad.
  
• Warp Spiders. The only aspect that still works exactly like it used to. They're still pretty awesome (and brutal against light vehicles and all infantry) in big squads, a reminder of just how powerful the ancient eldar once were (yes, that is on two levels).
  

I love the wave serpent with all my heart, but it's just not usable now, as the good eldar are the ones that won't benefit from it. I say drop it and the Avengers (which is a shame, I have 20 DA gathering dust. It's sad). Pick up either rangers or jetbikes, whichever you prefer and add an aspect squad to taste, or none.