Seems like quite a case of optimised Ork list Vs. a Fun Dark Eldar one. That being said, I still think the
DE would of had a better chance if he changed a few things. If you tell him these things is up to if you want to lose next game
I feel his wasn't using Vect efficiently, you pay a lot for his
CC goodness and he wasn't in combat till turn 3 when he could of been there turn 2. What i'd of done is swap the warriors for a unit of wyches to rock with Vect (9 wyches with Hydra gauntlet & Hek with Venom blade us 115pts) that makes much better use of his combat ability. On the charge with extra strength from drugs (About same as all other combat drugs like extra attack or re-roll to wound, just easier for me to math out) they do around 17 kills on Orks (8 wyches with gauntlet giving 3 extra attacks = 10 dead orks, Succubus another 2, Vect 5 ish) on average, not including pistols. That's some amazing combat potential he was wasting. Also he should try make the points for nightshields, they work wonders against orks with there 18 inch guns with good pre measuring.
Over all well played. I think you might be lacking anti High
AV because if he played Vect aggressively he could of had his pick of any unit you had with little difficulty. For you i'd drop the Mek down to bare minimum, CFF and maybe a burna. That way by knocking off a few lootas you can afford a second Mek with a CFF, so you always have a back up plan.
Alex/