We're finally down to the end of the Troops for Dark Eldar (and that says something in its own right). Both Hellions and Wracks are optional Troops for Dark Eldar which can be unlocked by taking either a Haemonculus for Wracks or the Baron for Hellions. Both of these 'parent' units are good in their own right so these FoC movements are an excellent addition to the Dark Eldar codex and don't really come with a huge cost. Both optional Troops have a lot of similarities and differences to both Wyches and Kabalite Warriors which will cover here. One thing they do have in common though is they aren't very good unless they are Troops. Dark Eldar Elite and Fast Attack slots are packed with other options and whilst these units make good Troops they don't make good Elite or Fast Attack options.
Wracks:
Wracks are uncharacteristically tough for Dark Eldar. They come with T4 and start off with FNP from a pain token. For 10 points that's pretty good. They also have two close-combat weapons which are poisoned and considering how easy it is to get them a second pain token (you've already bought a Haemonculus to unlock them), they can be decently potent in combat as well. Whilst WS4 helps here, their low strength (3), initiative (4), and save (6+) combined with no Fleet means they aren't nearly as good as Wyches in terms of staying power. Although they are certainly better against high T targets and benefit greatly on the charge with poisoned weapons and two pain tokens, Wyches are generally going to be the better combat unit with better I, 4++, 2-4 special combat weapons, fleet, grenades and combat drugs. The lack of Fleet also slows down ICs which may want to tag along such as an Archon or Succubus though there are generally better units they can hang out with anyway. What this all boils down to is Wracks really shine for Dark Eldar outside of combat due to their T4 and FNP but are still effective mop-up or supporting assault squads.
How then do we best utilise Wracks? They aren't terrible at combat but other units are better tarpits (Wyches) against better units (rocks) or are simply better combat units (Beastmasters, Hellions, Incubi). Furthermore, they have no shooting weapons outside of a template every five guys. Sure they are an excellent unit in combat against MCs due to their poisoned weapons but low I and no invulnerable save hampers them a lot. As said before, their high toughness and FNP makes them pretty hard to take down at range (especially in cover) and since they are capable of taking transports, well they become excellent and cheap objective sitters who are mobile and pack a decent amount of poisoned attacks in combat. This makes them decent clean-up crews or simply sitting in backfield camping on objectives (inside or outside of transports) as small squads. Large units are an option but makes them much more midfield oriented ergo Space Marines and whilst they may be as survivable as Marines when in cover with more combat potential than Marines, the rest of the army is not. For this reason I'd generally steer away from large Wrack units and leave tarpitting/combat to Wyches. With that being said a 5-man squad with Liquifier in a Raider for anti-tank is an excellent objective sitter which also has cover busting and mop-up combat ability.
Again, as a front-line assault unit these guys aren't too flashy. Their real strength comes from being very survivable at range, particularly in cover. Camp a squad of these guys on an objective and continually go to ground and you've got a 3+*/T4/FNP unit for 10 points a model. Taken. This forces your opponent come and remove them yet they are still capable of redeploying quickly with their transport which also provides downfield firepower. In terms of upgrades, there aren't many available to Wracks. The Liquifier is a nice template which is an excellent option to give the unit that little more flexibility whilst still keeping it cheap. Like many Dark Eldar units, the upgrade character (Acothyst) is a good addition for the extra pip of Ld and that's about it. Whilst the Acothyst can bring a combat weapon to play and make the Wracks a bit scarier in combat, it also can be quite expensive and still doesn't make them a potent offensive unit. Generally this option can stay home as there are better upgrades elsewhere. If you were planning on the full 10-man unit though I'd spend the extra 10 for Ld9.
Hellions:
The most glaring issue for Hellions: no special weapons. This is the primary reason they are a terrible Fast Attack choice. This will be covered more in the Fast Attack review but Fast Attack is where your Heat Lances are and if you're not taking Heat Lances you should be taking Beastmasters more often than not for the pure win they are in combat. Even then, taking Beastmasters has a huge opportunity cost in no heat lances.In the end, Hellions just lose out to these units but when we move them to Troops and build our army around them? Cha-ching! This is important though, like Wyches you really need to consider the army you're going to build around Hellions. Unlike Kabalite Warriors or Wracks who can fit into a lot of different list styles easily, Hellions need the army to really be based around them. This reasoning is two-fold: 1) no specials which means you have to have anti-tank elsewhere. 2) less transports which means less anti-tank and less saturation. With this in mind let's look at the actual unit.
Hellions are jump infantry (hence why they cannot take a transport!) who are very fragile. Unlike Reavers who can get a 3+ turbo-boost save and come with skilled-rider, Hellions rely on their bare T3/5+. This leads to a conundrum as small units which are easy to hide get torrented away quickly whilst large units who can take casualties are much harder to move without landing in terrain. Luckily there is a solution but we'll look at that later. An early pain token can really help their survivability like most Dark Eldar but they still baulk at S6. Moving beyond their deficient defenses (I mean, is that really anything new for Dark Eldar?), Hellions have quite good anti-infantry. They carry assault 2 18" poisoned weapons which combined with their 12" move means a fair amount of anti-infantry firepower on the go and is backed up by their solid combat presence. Due to their glaives, Hellions have S4 in combat which is a huge plus for Dark Eldar (note: the glaive also adds +1A; this seems to be missed a lot). Combined with good WS and I and Hellions look to put the hurt on the opponent before they can swing back. This proficiency in combat is further enhanced by combat drugs and pain tokens which can give a potential S6 on the charge (stationary vehicles watch out).
Before we look at what Hellions are good at I'm going to look at the upgrades (or lack there-of) for Hellions. Once again, the lack of special weapons is huge and this leaves the only upgrade for the unit being the Helliarch. Once again, this ups the Ld of the unit to 9 and has the option of bringing a special combat weapon. The best option here really is the Stunclaw. The other options loses you the option of having high strength attacks on the charge and whilst give you the option to punch through armor (power weapon and agoniser), aren't really going to make the unit scary in combat. The Stunclaw however allows the unit to stay in combat with an IC during their opponent's turn to minimise damage from combat and shooting whilst also being able to single out said IC. Not always reliably as there isn't always an IC around but a great option to have. The Helliarch also can take a Phantasm Grenade Launcher which is important on large units to ensure their high I comes into play (remember though the Baron comes with one as well). That all being said, it is again hard to justify the point upgrade for small squads. The extra Ld is nice but when you need to take an Ld check on small squads, they aren't exactly at fighting strength anymore.
So gameplay. Whilst Hellions aren't an awesome combat unit, they are very effective at putting out a lot of medium strength hits before foes have a chance to swing and are very capable of getting the assault off due to their 12" move + Fleet. More importantly however they are not just combat units and are quite capable of putting out an annoying amount of poisoned shots per turn at a decent range. What this then boils down to is Hellions are excellent at harassment. As a small unit you can easily get cover and have enough shooting and combat firepower to be a mild threat to your opponent (and be scoring), particularly to backline units. Hellion units which get a good combat drug roll (+1S) and pain tokens quickly can become even more bothersome due to the sheer amount of S6 they can throw into vehicle rear armor. However, as your only scoring option this is pretty flimsy. In a scoring mission your opponent will target and eliminate these squads and whilst this may leave the rest of your army to smash his army to bits, you have no chance of winning based on objectives.
This is where a big unit of Hellions comes in. Notice it's not a plural. To access Hellions as Troops you have to take the Baron and the Baron makes a unit of Hellions that much more potent. Not only is he pretty decent in combat (and cheap as chips) he gives the Hellions grenades, skilled rider, stealth and an improved hit and run. Suddenly an annoying unit is now super annoying and quite dangerous and quite a bit larger. Baron allows a large unit of Hellions to overcome their main weakness in not wanting to move into cover. 1/36 chance to die is a very good chance of not dying and combined with stealth (I'll take that 3+ save thanks) and the anti-infantry ability of Hellions both at range and in combat, and you've got an excellent anchor unit which scores. Surround this unit with a couple smaller squads of Hellions for harassment and the core of your list is set.
Again; Hellions are not a mainstay assault unit even with FNP and Baron. Dark Eldar are not Marines and whilst Hellions are excellent on the offense, bite off more than they can chew and they will die and die quickly. If you're going to run Hellions and expect them to work in protracted combats you're going to need to support them. However, a much better use is using them as harassment. Small footprints, fleet, 12" move and Hit & Run combined with proficiency at range and in combat against infantry makes them an annoying unit to deal with which can allow the rest of your army to operate more effectively. Here is a Hellionway example list at 1850 (and 1500 from Stelek).
Conclusions:
Having optional Troops really opens up a lot of doors for an army as it spreads the FoC out. Without the ability to move these guys around I don't really think they'd see the light of day simply due to opportunity cost. As Troops however they play specific roles quite well and Hellions in particular allow a very different army to be built around them. It is important to remember when using these units to make sure their parent units are also integrated into the list. This isn't too hard with the Baron as this was outlined above but Haemonculus' really should have a place to start the game with where they can really benefit a unit and the list overall.
With four solid Troop choices it can be difficult choosing what you want, particularly with the flexibility of Kabalite Warriors. In the end look at what your army needs. Whilst Warriors in particularly can diversify, the other Troop options have quite specific niches where they excel. Hellions in particular need to be built around and Wyches, unless being used as simple road bumps, should take serious consideration as well. By ensuring you pick the right Troop choice to compliment your army, it will run a lot more smoothly and ultimately lead to a more coherent and effective force on the tabletop.
