After some extensive testing, I am happy to provide you with a fairly balanced, fun to play Decurion Detachment for Dark Eldar. Here are the rules:
Dark Eldar Ancient Predators
This is a special type of Detachment that must inculde at least one Core choice and from 1 to 12 Auxiliary Choices and up to 1 Command choice.
Ancient Predators must be your primary detachment.
Oldest Foe – if this detachment is your primary detachment, you may reroll the result when rolling on the Warlord Traits table.
Core:
The Vile Parade (1-3)
The Decadent Aristocracy
1-3 Archon
0-1 Dhrazar, Master of Blades
Court of the Archon (at least 4 models, In Any combination) for each Archon
2-5 units of Kabalite Warriors
1-3 units of Trueborn
1-3 units of Incubi (if this Core choice includes 3 full squads of Incubi, All Incubi models have Ramapage)
Benefits:
Blinding Speed - Units of Kabalite Warriors and Trueborn benefit from 5+ Cover Save.
Ready for War – Upgrades for dedicated transports for units from this Formation can be taken for free.
Slay the Barbarians – once per game, at the start of your Shooting phase, All models of Kabalite Warriors and Trueborn In this Formation gain +1 BS until the end of turn.
Maidens of the Arena
1-3 Succubus (one of the Succubi may be replaced by Lelith Hesperax)
2-5 units of Wyches
1-3 units of Hexatrix Bloodbraids
0-4 Beastmaster Packs
Benefits:
Blinding Speed – Units of Wyches and Hexatrix Bloodbraids benefit from 5+ Cover Save.
Hyped Up – All non-Beastmaster Pack units from this Formation roll twice on the Battle Drugs table and benefit from both results. Reroll duplicates. Beastmaster Packs In this Formation (except Razorwing Flocks) gain Battle Drugs special rule. (For the purpose of BD bonus, they always benefit from the first roll)
Apex Predators – once per game, you must at the start of your Assult Phase, all units of Wyches and Hexatrix Bloodbraides that include a Succubus (or Lelith) from this Formation gain the Shred special rule until the end of your turn.
Coven Lords:
1-3 Haemonculus (One of the Haemonculi may be replaced with Urien Rakarth)
2-4 units of Wracks
1-3 units of Grotesques
0-2 units of Talos or Cronos
Benefits:
Units form the Coven Lords formation benefit from a different Power from Pain table:
1. None
2. Fearless
3. Fear
4. IWND
5. Zealot
6. Eternal Warrior
Dark Fervor – models In this Formation have Furious Charge, except Talos and Cronos models. In addition, Talos and Cronos models from this Formation gain Power from Pain.
Zeal of the Deviant – once per game, at the beggining of your movement phase, each model In this formation gains Fleet until the end of your turn.
Auxiliary:
Gangs of the Dark City
1-3 Units of Reavers
1-3 Units of Helions
Hyped Up - All units from this Formation roll twice on the Battle Drugs table and benefit from both results. Reroll duplicates.
Joyride – Units of Helions In this formation gain Jink special rule.
Fist of Khaine
1-3 Ravagers
Fluid like the Blood – for each other model from this formation within 6’ of each other, models from this formation may shoot one weapon at full BS, even if they Jinked or moved at Cruising Speed.
Hyperspeed Hunters
2 Razorwing Jetfighters
1 Voidraven Bomber
Speed of Death – for each other model from this formation within 6’ of each other, units shooting with Interceptor or Skyfire special rule that target models from this formation get -1 to their BS.
Gang Mentality – models from this formation gain +1 BS when shooting at units/vehicles that have shot at models from this formation.
Skyblade
1-3 Razorwing Jetfighters
All models In this formation gain Vector Dancer.
Monstrous Wonders
2 Talos and 1 Cronos
Models from this formation form an unit, even if it is not normalny allowed.
Towering – models In this formation cause Fear and may Re-roll Charge rolls.
Beautiful Malice – Cronos Spirit Syphon affects friendly models within 12’.
Scourges (no New rules here)
Mandrakes
Gathering Shadows – if a unit of Mandrakes Has 10 models, Independant Characters that join that unit gain Infiltrate.
Command
Corpsethief Claw
May be taken Only if your Detachment includes Coven Lords.
You can find the rulet of Corpsethief Claw In Haemonculus Covens suplement.
Eye of the Crone
May be taken Orly if your Detachment includes the Decadent Aristocracy.
1-3 Trueborn units
Each unit may include no more that 5 Trueborn. All Trueborn must Take Dark Lances, even if normally it is not allowed and may not be joined by IC.
Masters of the Hunt – Units of Trueborn from this Formation gain Infiltrate and Stealth.
Bloody-Handed
May be taken Only if your Detachment includes Maidens of the Arena
1-3 Hexatrix Bloodbraids units
Hyped Up - All units from this Formation roll twice on the Battle Drugs table and benefit from both results. Reroll duplicates.
Speed of the War God – All units from this Formation have 5+ Invulnerable Save outside of close combat and gain Hit & Run.
If you feel like something is overpowered or underpowered, send me a message to mightydoughnutchannel@gmail.com or on my wargaming blog - warlockpurple.tumblr.com
Feel free to share this idea for a Detachment, just remember to add a link to my wargaming blog, so we'll be even.