Horus Heresy: Building and Expanding Your Age of Darkness Boxset (Traitors Version)

Welcome back to Goonhammer’s series for aspiring Praetors. We know that the Horus Heresy system can seem intimidating to players unfamiliar with its particular quirks, but this series aims to equip you with everything you’ll need to play out epic clashes on the battlefields of the far future with your very own army. In this series, we’ll be walking you through how to build your force and command it to glory, including everything from units to tactics to lead your army to victory. 

The enormous Age of Darkness boxset is currently on preorder for those of you looking to leap into the 2nd Edition of Warhammer: The Horus Heresy. But you might be wondering exactly what you should do with that box when it arrives. What’s the best way to build it? What units should I pick up alongside it? This article tackles these questions, and works legion by legion to pull out the best way to approach the box, what to pick up to add into it, and what your priority purchases should be going forward.

It’s worth saying that any legion can pretty much do things in any way you like. Each legion was tens or hundreds of thousands of space marines, and there were enormous variations among them. You can build a Raven Guard terminator siege force if you want, or a Death Guard assault company, or anything else you fancy. But each set of legion special rules and units definitely encourages a particular play style and this guide tries to help you lean in on what makes your legion stand out while using the same box as everyone else.

If you haven’t picked a legion yet you should check out our Liber Astartes and Liber Hereticus reviews which give you an overview of them all. As an additional note we’d strongly recommend magnetising the Contemptor that comes in this box, so the recommended loadouts aren’t required to be glued in place.

This is one part of a two-part series, covering the Traitor Legions. If you’re interested in reading about the Loyalist Legions and how to build those out, you can find that article here.


Emperor’s Children

Credit: Robert “TheChirurgeon” Jones

Proud and vicious, the Emperor’s Children are certainly one of the most stylish of legions and this box can be capably converted to support their flashy shenanigans.

You’re going to want to build 10 of your Mk VI marines as a tactical squad, giving all of the marines chain bayonets and your sergeant the power sword. The buff to initiative benefits all the melee weapons, but the truth is that anything your sergeant has a hope of killing (and your unit winning the combat against) is going to murder you before you can swing the power fist in most cases. There are a select number of units when Initiative 2 fists vs Initiative 1 fists are worth it, but they’re few and far between and even if your sergeant manages to wound (or even kill) another sergeant, the rest of your squad is going to evaporate fast enough.

You could build another 10 tacticals and then fill out with your choice of heavy or tactical support squads, but I would recommend something a little different. If you can, find a bunch of alternative arms and equip 20 of them with chainswords and bolt pistols and run them as Despoilers, then put this large unit in the Spartan with the sword-wielding praetor. Probably strap as many lascannons as possible to the Spartan, as you’re going to need it for anti-tank support. Then with your last 10 build a rotor-cannon tactical support squad – this is a wonderful source of pinning. Hose a target down with fire to pin them, then pile the despoilers out of the Spartan and into them for the bonuses from Spite of the Legion. The other praetor can be run as centurion and ride with the support squad for some added protection.

If you can’t find that many chainswords, consider instead making 10 or even 20 of the Mk VIs into veterans. Throw as many power swords as you can find on them, give them some combi-meltas if you can, bolters if you can’t, and throw a special or heavy weapon on the maximum number. These units will do good work in an army of this kind.

You’ll need some transport for an army like this – 2-4 rhinos (depending how you’re building your units) is pretty much a must as a next purchase. If you’re running the despoiler squad then you can sell the cataphractii to fund some of this – cataphractii aren’t great for Emperor’s Children because they’re slow and a bit lumbering. If you end up running more tacticals or veterans however, instead build your cataphractii with fists (maybe chainfists if you expect to fight a bunch of vehicles) and put them in the Spartan to get them around. The fists will strike at initiative 2 pipping other terminators (your biggest infantry threat) to the post and hopefully taking enough of them out to blunt the damage they do to you.

Your contemptor would be best built with a pair of power fists, or a power fist and a chain fist, if you can find a spare from somewhere (plasma or melta in the hands for preference, and with the launcher on top if you like it, it’s never a bad get) because you want it to get stuck in, and fists are the way to do it. If you can’t then there’s a decent argument for any of the weapons, but the melta will give you some decent anti-armour to balance out the power fist on the other hand.

Iron Warriors

Credit: Robert “TheChirurgeon” Jones

Tough, brutal and unrelenting, the Iron Warriors are looking to maximise the sheer damage output of their shooting.

You should start with a couple of tactical squads with the sergeants having a power sword each. You can add bayonets or chain bayonets if you like, but these guys are going to be primarily shooting stuff and holding objectives, so it’s not as important for some legions.

The other 20 Mk VIs should almost certainly be built as support squads of one kind or another. The +1 Strength against Dreadnoughts, Automata, Vehicles and Buildings means there are certain heavy weapons with a particularly good breakpoint. Autocannons are great for Iron Warriors, though both Plasma and Missile Launchers do good work. You don’t really want to go for anything too close range because you’ll be mostly keeping your distance with these guys. 10 Autocannons and 10 Missile Launchers will set you up very nicely. This same logic can extend to your contemptor – autocannon is very good, and you should almost certainly put the havoc launcher on the top – it’s not an amazing anti-armour weapon but the +1 S is enough to pump it up to be glancing light vehicles.

With all that anti-armour shooting, and the Spartan adding to it, you should probably run your terminators in an anti-infantry role. Load all ten up with Lightning Claws and you will not regret it as they chew through baseline marines at a hell of a rate. Throw the axe lad in there with them to lead, while the sword praetor goes with one of the tactical squads or babysits the heavy squads. For the Spartan consider the heavy bolters for more anti-infantry firepower.

For your next purchases some more armour is a great shout – a Kratos is very nice indeed for Iron Warriors. Also consider a couple of Land Raiders to throw your tactical squads in.


Night Lords

Credit: Robert “TheChirurgeon” Jones

They’re creepy and they’re kooky, mysterious and spooky, they’re altogether ooky: The Night Lords.

Another challenging legion for this box, the Night Lords can lean into two forms of lightning fast shock warfare: all the bikes; or lots of jump troops. The contents of this box really doesn’t lean into “bikes” very well, so instead let’s look at how we can build a strong core onto which we’ll add shock assault units.

First up you should probably build a pair of tactical squads of 10 marines each. These you should gear up with chain bayonets and a vexilla, anything to win a combat. Then put some trophies, skulls, little bits of flayed flesh, whatever you can convert, onto your sergeant – you’ll give him the Trophies of Judgement upgrade granting him Fear (1). This combined with the vexilla will make it more likely you win combats and then more likely your opponent will run and you can try and sweep them and destroy them. You don’t have to get very lucky for this to work on units much better than a tactical unit – a charge grants enough extra attacks to match a veteran unit. You’d be surprised how much stuff this can clear. If you wanted to lean in to this you could bulk both units out to 20 each, ensuring they will almost certainly outnumber any unit they hit, giving them then +1 to wound when they do from your legion trait. The other option is to build 10 of the other marines with rotorcannons and 10 with missile launchers to throw down as much pinning as possible. This also gives you some flexible anti-armour.

Terminators are going to shine here with lightning claws, because that +1 to wound counteracts the worst element of them as a weapon (strength: user), so I’d do that. Definitely decorate your sergeant with trophies to give the unit fear. Since you’ll be lacking much anti-armour punch but want to move fast put mostly anti-tank weaponry like meltas and lascannons on your Spartan, but consider a combi-grenade launcher on there too so you have an extra source of pinning if you can find the parts.

If you want to go a completely different route, sell the Spartan and buy Sevatar and another big unit of terminators (this time probably with chainfists and combi-bolters). With Sevatar as your warlord you’ll be able to deep strike those units of terminators onto the battlefield.

Your next purchases are probably Contekar Terminators, Night Raptor Squads and Terror Squads, as well as any transport needed to carry them. These are all fantastic unique legion units and getting some should be a priority.


World Eaters

Credit: Robert “TheChirurgeon” Jones

Ferocious and violent, loving to get stuck in up close, the World Eaters are another tricky proposition for this box set.

Unless you want to lean into the early mode of the World Eaters, when they were more regimented and before the madness of Angron began to spread, you’ll probably want plenty of troops that get stuck in up close. Therefore, if at all possible, you should try and find a good source of arms, chainswords or axes and boltpistols to arm as many of your 40 Mk VIs as despoiler squads, or add some jetpacks for some assault squads. If you can do this simply make two large units of despoilers or assault marines – you won’t regret the opportunity to get up and close and rip and tear.

If you can’t get fully 40 sets of arms, but can get, say, 20, then I would build one large despoiler squad, one tactical squad with chain bayonets, and then 10 tactical support marines with rotorcannons to pump some pinning into enemy units before the rip and tear lads slam into them. If you can’t find any or they’re not in your price range (remember that Forge World do sell chain axes and bolt pistols… for £17.50 for five. So if you’re made of money that’s an option I guess) then I would simply make two 20-marine tactical squads with chain bayonets. It’s still a staggering number of attacks on the charge, enough to make even a terminator squad blink, and you’ll find they’re a lot more resilient in these large blocks.

As for your terminators I’d recommend running them with lightning claws – ten World Eaters terminators with lightning claws throws out a genuinely horrifying number of attacks. If you can swap the Cataphractii for some Tartaros then maybe consider doing that because the ability to sweep after a combat is very useful, but if you can’t they’ll still look cool and do horrifying damage. Throw them in the Spartan with your axe praetor (and consider leaving off the cloak of the sword praetor, demoting him to a centurion and running him with one of the tactical squads), and they’ll do work. You’ll be lacking anti-tank punch so maybe lean into lascannons and other anti-tank weapons on the Spartan.

For the Contemptor if you can rustle up another power fist and run them with two that’d honestly a very solid investment – a power fist and a chain fist would be even better. If you can’t then something that will hurl out a lot of shots as you run towards things screaming is great, so maybe a heavy bolter, autocannon or a kheres if you can find one from somewhere else.

Your next purchases should really be some more close combat units. Assault marines are a great choice, as are the special legion unit Rampagers (either the Forge World models or ones you convert yourself). You’ll want some transport for the Rampagers if you get some – a Land Raider is the only real choice.


Death Guard

Credit: Robert “TheChirurgeon” Jones

Tough and unyielding, the Death Guard are one of the most resolute of legions and their special rule means building them in particular ways yields good results.

Probably the best way to build your Death Guard Mk VI is just with two 20-marine tactical squads. I wouldn’t bother with chain bayonets, but bayonets are a reasonable add – it’s just not worth the points to give them upgrades they’re likely not going to use. These will footslog along while the terminators (powerfist and combi-bolter for flexibility is a good shout) ride in the Spartan. As for the Spartan you should consider a heavy flamer on your pintle mount to swap for a heavy alchem flamer which is a great upgrade. The Contemptor can take whatever you fancy, but I would put a heavy alchem flamer in the fist and pair it with an autocannon for flexibility and light vehicle hunting.

For your next purchases I would consider getting hold of more Mk VI bodies and the heavy weapon upgrade kits. There are some niche uses for the special weapons, but the ability to move and fire heavy weapons on all your troops isn’t to be underestimated. You might also want to pick up some of the legion specific terminators, or maybe some artillery like the Arquitor.

Thousand Sons

Credit: Robert “TheChirurgeon” Jones

Mystic and secretive, the Thousand Sons are unusual in their psychic potential and so it’s suitable that putting the box together to best suit them requires a little wizardry…

Let’s start with the praetors that come in the box, because you should really consider kitbashing one or both of these. Keeping one of them as a praetor is absolutely fine, but you should consider converting the other to be a librarian as more psychic powers is generally a good idea for the Thousand Sons. The 40k range is a goldmine for bits for these guys and a fair sight cheaper than the Forge World range, so have a look at those kits to see what you can grab.

For your Mk VI you should build out a couple of 10-marine tactical squads. You can give these no upgrades, keeping them cheap, and then giving them the Corvidae minor arcana to effectively snipe enemy units, or Raptora to make them a little more survivable for holding objectives. Alternatively you could give them chain bayonets and Pyrae for a little more close combat punch. Some rhinos for these to ride in is a good first purchase. If you want to run large units instead then run two units of 20 all with chain bayonets and vexilla and give them Pavoni to footslog up the board at speed to where they need to be. Whatever you do the extra point a model to swap their bolters for Asphyx bolters is definitely worth it.

If you haven’t built out all the Mk VI then grab a Special Weapons Upgrade Kit and then build 10 of them with plasma guns and run them as Aether-fire blasters. These will do work. For the rest it’s something of a matter of taste, but I think volkite chargers, melta and rotorcannons are all good options.

If you can, sell the Cataphractii terminators. They’re not bad, but Sekhmet Terminators are so much better. The Forge World models for them are very nice, but honestly you can happily buy the 40k Scarab Occult Terminator kit and run that as Sekhmet and it will be fine – the weapon choices pretty much all line up absolutely fine. This is a great move as it gives you an amazing block of heavy infantry to throw into your Spartan (which you should build tooled for anti-tank weaponry with lascannons and meltas on everything you can put them on). If you want to really lean into the Special Wizard Stuff aspect of the legion, also sell that Contemptor and buy an Osiron pattern Contemptor because how cool is that model. Otherwise just build it with plasma in the fist so you can swap it for Aether-fire and throw a lascannon on the other arm for more anti-tank punch.

Your next purchase should either be some more vehicles (a Kratos is nice) or more Sekhmet, with the intention of pushing towards Guard of the Crimson King. You should 100% buy Magnus the Red eventually if you got that way, but Ahriman is a good pick up in the meantime.

Sons of Horus

Credit: Robert “TheChirurgeon” Jones

The iconic Bad Guys, the Sons of Horus are extremely tough in close combat and their vehicles sure do like ramming things. As such you want a bunch of units that flourish in close combat and aren’t afraid of getting stuck in.

Your terminators were going to be tough anyway, but the Sons of Horus make these chonky lads even tougher. Combi-bolters and power fists are a good choice for this unit to take advantage of the Death Dealers advanced reaction if you get an opportunity, but All Lightning Claws All The Time is also 100% a cool and good way to go. Bundle them into your Spartan (with heavy bolters if you’ve gone for fists and lascannons if you go for lightning claws to balance out the focus you’ve taken on those riding inside), ram that puppy into anything you like then bundle the terminators out into their mashed faces. Good times.

Your Mk VIs I like in a couple of big 20-marine tactical units, all with chain bayonets and vexillas. It gives them a reason to slam hard into enemy units and they’ll be very hard to shift off objectives with the buff to ranged defence from Heart of the Legion and their increased survivability in melee from the Sons of Horus trait. The contemptor can ably assist with pretty much any set up that includes at least one fist – just be sure to charge early and charge often.

Honestly this box set is built for the Sons of Horus, so don’t be afraid to build it without too much fancy stuff added in. For your next purchases it’s hard to go wrong with a Kratos, more Mk VI if you can get them to add some heavy or special weapon punch, and maybe even big daddy Horus himself.

Word Bearers

Credit: Robert “TheChirurgeon” Jones

Demonic and destruction, the Word Bearers lean far heavier into the “nightmare horror” aspect of Chaos and the heresy than any other legion. As such this is a great legion to pillage Chaos Marine bits from 40k for and get some very spiky lads into the fray.

A great purchase right away for Word Bearer is a box of Chaos Space Marines. You get a load of cool shoulder pads, some awesome heads, cool chaosy vexilla, and of course a bunch of chainsword and pistol arms that you can plug onto 10 of the Mk VI bodies to build despoilers. The chaos melee weapons are great “tainted” weapons for your characters too. You’ll also find you have a bunch of Chaos Space Marine bodies left over, and careful allocation of bits can leave you with 10 Veterans ready to bring horror and madness to your enemy. A couple of rhinos will make these guys nicely mobile.

For the rest of your Mk VIs (or all of them if you don’t want to get spiky with it) I would build two 10-marine tactical squads with chain bayonets and a vexilla each to take advantage of the legion special rule, and buy them a rhino each so they can go grab objectives fast. If you build some despoilers you’d be silly not to kit out the last 10 marines with each plasma guns upgraded to Warpfire blasters from the special weapons kit, or missile launchers from the heavy one – you want that pinning to make the most of Spite of the Legion. If you didn’t then doing both is actually a very solid plan anyway – warpfire blasters are fantastic, and missile launchers are very versatile.

Your terminators are probably best off adding some extra anti-tank punch with chainfists and combi-bolters, and they should ride in your Spartan which you can equip with All the Lascannons for added punch. Your contemptor should put plasma in his fist (to upgrade to warpfire) and then he can rock whatever you fancy on the weapon arm.

The praetors are prime candidates for kitbashing, especially if you did get that chaos space marines kit – a horned helmet and a tainted axe is a cool as hell build, and you’ll have great shoulder pads to round it out. This Alpha Legion Armistos was kitbashed just from parts found in the chaos space marine kit, the axe praetor from the box, and a spare heavy bolter I had lying around.

Alpha Legion Armistos. Credit: Lupe

For future purchases consider hanging on for those new Chaos Space Marine Possessed models which will make amazing Gal Vorbrak. Alternatively round out your assaults with an Ashen Circle Squad who are great up close and personal combatants.


Alpha Legion

Credit: Robert “TheChirurgeon” Jones

Confusing, confused and contradictory, the Alpha Legion are the masters of deniable warfare. They can make a neat little core of an army out of what’s in the box here, but what you buy next will determine a lot of what you build.

If you’re planning on picking up Armillus Dynat or Alpharius right away then you can build the box out with the assumption you’ll be able to infiltrate some units. If you do that then you should build only two 10-marine tactical squads, with your choice of bayonets or not depending on if you like them on the minis. Grab a couple of rhinos and have them be your mad dash to objectives to hold them. Then get the special weapons upgrade kit and consider a unit of 5 melta guns, a unit of 5 flamers, and a unit of 10 plasma guns. You can infiltrate all three and cause chaos in their lines right from the start.

If you’re not then I would instead build two 20-marine tactical squads, loaded with chain bayonets and vexilla. They’ll footslog up the board and look to grab objectives, relying on their overall toughness and the Alpha Legion trait to protect them.

Either way you’ll outfit the terminators with either lightning claws or chain fists and combi-bolters – the choice really is yours. You can load them in the Spartan and you should equip either heavy bolters or lascannons depending on if you went anti-tank (chain fists) or anti-infantry (lightning claws) on the terminators, looking to even out the damage output you’re generating from the unit. The contemptor can run pretty much however you please, though autocannons make good use of the manoeuvrability of the dreadnought to hunt light vehicles.

If you haven’t chosen Dynat or Alpharius as an early purchase consider getting some extra anti-tank support – a Kratos is a great choice, as would be some more contemptors (and the Alpha Legion contemptor is exceptionally pretty). Don’t forget your Rewards of Treachery, so have a look at what legion specific unit from another legion you want to pick up.

The Sky’s the Limit

There’s a lot to cover here, and your options are pretty much limitless when it comes to expanding the box contents. That said, hopefully we’ve given you some good food for thought on how to expand your forces out from this boxed set. Be sure to check out the Loyalist article for more on building around them, and as always if you have any questions or feedback, drop us a note in the comments below or email us at contact@goonhammer.com.