Tournament test battle vs Dark Eldar

More than a week ago I played another 6th edition game. I once more used the list that I plan on taking to the Challenge 7 tournament. My opponent brought a dark eldar "bane of my existance" list consisting off the baron, a homunculus, a large unit of helions, a small unit of wracks, two units of wyches in raiders, two units of trueborn with blasters in venoms and two ravagers. We played the first mission of the challenge 7 missions. In this mission there are 5 objectives (each worth 3 mission points) as the primary objective. You can score 5 additional points if you get slay the warlord (3 points if you lose your own warlord afterwards). The deployment was Dawn of War. Mysterious objectives were in effect but we forgot about them (6th is still new to us).

We placed objectives mainly on my opponent's board edge and near the middle of the table. My opponent won the roll to deploy first. He deployed all of his units with the ravagers, the wracks with the baron in the middle, the venoms and the raiders behind a building on his right and the helions with the homunculi on his left. I almost deployed the long fangs with missile launchers but decided not to in the end. I got a worthless warlord trait that lets my warlord and his unit outflank. My opponent got the one that allows him to reroll run dice. My opponent got +1 WS for this combat drugs.

My opponent had first turn and I then decided to seize the initiative, which was a big mistake I think as I did seize. The better option would have been to either not seize or to actually deploy the long fangs and maybe even a grey hunter squad.

On my first turn I dropped down the melta grey hunters with the runepriest next to his venoms. I dropped a squad of long fang missile launchers but they scattered back. I also dropped down Logan and the multi-melta longfangs. With all my shooting I succeeded in removing one hull point from a raider and one hull point from a venom. Epic fail! The snapshotting missile launchers took down the homunculi who was the first model in the unit of helions.
In my opponent's first turn he let the baron join the helions, taking the wrack's pain token along. He then moved one raider forward towards my longfangs. The witches got out and assaulted the longfangs. His other shooty units got in line of sight of my longfangs and Logan. The helions blew away Logan who failed his third and fourth armour save and then continued to roll ones on his look out sir but making the saves. Then the rest of his army shot at the longfangs from the other side, taking them and Logan down without needing an assault. His other wytches got out of their raider and assaulted the runepriest and the grey hunters. I had already lost several grey hunters and the wolf guard to shooting.

On my second turn both the grey hunter squads dropped down in front of his helions. I unloaded with both units and only killed three helions. He made an exceptional number of cover saves (improved by the baron) and feel no pain whenever he failed a cover save. My second squad of missile launcher longfangs dropped down in terrain and shot down a venom. Combat between the wyches and the grey hunters with the runepriest continued.
In my opponent's second turn, the helions turned towards one of the grey hunter squads and between shooting and assault, wiped them out. I even killed my own plasmagunner who overheated in overwatch. He shot the rest of his army at the second grey hunter squad and the missile launcher longfangs. Only one grey hunter remained. Both squads failed their morale checks and ran towards their board edge.

On my third turn my fleeing units regrouped automatically. The lone grey hunter moved up and assaulted the wracks, shooting one down with his pistol but failing to kill the other one in assault. Whatever I still had left that could shoot, mainly drop pod stormbolters, shot at his vehicles, taking at least one down. The runepriest and the wyches were still in combat. I kept making my 2+ armour saves while I couldn't hit a dark eldar if my life depended on it.
In his turn, the hellions and the baron assaulted the lone grey hunter locked in combat with the wracks and killed him. He also started to take down the drop pods and the remaining long fangs.

On my fourth turn, I had almost nothing left, let alone something that could move or shoot. So my turn went by really fast.
In my opponent's turn, the baron and the hellions made it to the combat with the rune priest and that was the end of it. I had only one or two drop pods left so we called it.

Dark Eldar is still a bad match up for my army. They can pack sooo much firepower and my force is still to elite for that. The baron and the helions got even better this edition, especially if you can get them into cover. Yes, they have to take dangerous terrain tests but the baron lets them reroll those and then they still have an armour save and a feel no pain roll so the chances to lose a model are very slim.