Everything in an Eldar army must have a role. A precise role. Unlike some other armies, the Eldar army list consists of a wide selection of Specialists. Each unit has specialized in (mostly) one thing only. A good tactician can use this to their advantage and perform some very masterful maneuvers with astonishing results. An amateur could easily lose faith in them and give up.
It is very important to know what role each unit fills, and adhere to that. I cannot stress this enough. With a Space Marine army, you have much much more leeway. Even a devastator squad can hold their own in close combat... they're still Space Marines. That Strength 4, Toughness 4, Weapon Skill 4, and Power Armour help a great deal.
Space Marines are made to be flexible, to be able to adjust to changes in battle conditions.
Not so much with the Eldar. You have to be careful, calculating, and precise. Wrong or hasty moves can lead to disaster, leaving not much room for mistakes.
This being said, the Dire Avengers tend to be the most flexible group depending on how you equip your Exarch.
On to the Dire Avengers...
Dire Avengers have these nifty extended barrel Shuriken Catapults, which change the range from 12" to 18". This is great, as it allows you to play a 'cat and mouse' game with your opponent. Shooting at near maximum range, constantly retreating slightly just to keep them from charging... At Assault 2, this can be very effective. With 'Bladestorm' this is way way effective. Bladestorm adds another shot to the weapon's characteristics, making it Assault 3.
Given their weaponry and Exarch Powers (Detailed Below), Dire Avengers in 5th Edition make for awesome Objective holders/capturers. As far as objectives go, aim them towards capturing the mid-field and Enemy Deployment Zone objectives. You have other Troops units with longer range weaponry at your disposal to better hold the Objectives in your own DZ.
Exarchs are serious business, and must also be chosen carefully. Think of the role that the unit is to fill, and choose the equipment that will best help enhance that role. The choice you make in equipping your Exarch will drastically change the effectiveness and role of the Dire Avengers
On to the Exarchs:
There are three main options of equipment:
Shuriken Pistol/Diresword -10 pts
Power Weapon/Shimmer Shield -15 pts
Dual-Shuriken Catapults -5 pts
Each option changes the role of the Dire Avengers.
By taking the Shuriken Pistol/Diresword combo you expect to use the Dire Avengers in a dual role (Shooting and Assault), preferrably against characters or other models with more than one Wound so you can instant-kill them. To be honest, despite that I love the idea of an Exarch with a Diresword because it's so picturesque ... the rest of the unit isn't equipped to assault, they're basically just padding to buy your Exarch time to finish the job. Too bad they don't offer the Shimmer Shield with the Diresword.
By taking the Power Weapon/Shimmer Shield combo you expect to use the Dire Avengers in another dual role: Shooting and Stalling. The Shimmer Shield protects the whole unit in melee! Especially if you equip your Exarch with the Defend power (another 15 pts), your Dire Avengers have suddenly become very surviveable; perfect for tying up an enemy unit that may have been making an attempt at a softer target. This kind of strategy works well when you have a combat oriented group waiting just behind the main lines playing 'cleanup' *coughBansheescough*. This is the strategy I hope to employ; using them for their primary shooting role, but giving them the capability to intercept and hold a tricksy enemy unit for my Banshees to come clean up.
By taking the dual-Shuriken Catapults, you limit your Dire Avengers to ONLY a shooting role. This one was the most tempting for me. An Exarch with dual-Shuriken Catapults counts as having one Assault 4 Catapult. Assault 4! Imagine Bladestorm with that(+15 pts)! That would be 5 shots just from HIM! Equipping an Exarch this way is a very viable and recommended option, just keep them out of melee at all costs! Play the 'cat and mouse' game until your opponent is defeated. This game is possible with your 18" range Catapults, but note that it is NOT possible with the normal Guardians' Catapults. Range on those is 12". That's the magic number: 12. With a 12" range if you can shoot them, they can assault you next turn. 6" move + 6" assault. Dire Avengers are the only Troops Option that can play this tactic outside of Jetbikes; use it to your advantage!
All in all, for only 12 points/model, Dire Avengers are really awesome in an Eldar army. The only thing cheaper would be straight-up Guardians, and the difference is great.
