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Ossiarch Bonereapers: Army Guide, overview, units and more

This article will detail the Ossiarch Bonereapers army starting from its lore, describing the main units and their roles, how the army plays and finally our personal opinion of the army.

For a complete run-down of the different armies available in Age of Sigmar, consult our Age of Sigmar army overview article.

In this article we will refer often to Matched Play and other technical terms like allegiance abilities, command points, army roles in building a list, core battalions, Endless Spells/Invocations, etc. We assume the reader will be knowledgeable with those terms, otherwise please refer to the relevant guides for more details.

Age of Sigmar 4.0
This article has not been updated yet with the newest rules and discoveries from the fourth edition of Age of Sigmar. We will be reviewing all articles and updating them really soon.

Image from Warhammer Community

Overview of Ossiarch Bonereapers Army

Ossiarch Bonereapers are constructs created by Nagash aeons ago when preparing for taking over all Mortal Realms. They are efficient and disciplined killers and nothing can stand in their way. All who fall, are “recycled” and their bones used to expand their army.

They are a brand-new army introduced in 2019 that follows up some slightly older sculpts (Morghasts and Mortarchs) and you may think they are the spiritual successors to the Tomb Kings while differing on many aspects (no chariots to start with!). The army feels fresh but there are certain roles, like more artillery pieces and ranged units, that are still missing, waiting for the next wave of models.

Their discipline is transported in game rules by having a huge number of command points and abilities that can be used to improve their efficiency. This game style makes them a good army, but you will also need to track resources carefully to ensure all units receive the commands they need when they need them.

The new battletome resolves some of the issues that plagued this army in the third edition, putting them on par with the other armies.


Image from Warhammer Community

Lore of Ossiarch Bonereapers Army

Long ago, in the Age of Myth, Sigmar and his fellow gods created a Pantheon through which to rule the Mortal Realms in the spirit of evolution and collaboration. Nagash, the Supreme Lord of the Undead, while working with them recognising their temporary use, plotted and schemed to achieve his ultimate goal: a Necrotopia. This would be a universe entirely dead where all be one in Nagash, and Nagash will be all, finally achieving everlasting peace.

In order to submit all realms to his will, he created a secret army, extremely disciplined and experienced, by collecting any bones he could find and using the best souls of deceased mortals. Those souls were deprived of any humanity, with sentiments like mercy and compassion removed entirely to keep only utter obedience to Nagash.

The priestly cast of this new army, the Mortisan, are still today responsible to mould these bones and merge the souls to create the constructs that wage war across all mortal realms. It was not until the end of the Souls Wars that Nagash released this army into the world. At that time, the effect of the Necroquake made visible secret previously erased from memory by Sigmar and his allies. And between those, there was also the soul of the most powerful military leader that served Nagash: Katakros.

A horde of undead freed his soul from the Stormcast Eternals prison and Nagash created a new body for the his new Mortarch now able to lead his legions of death. The Ossiarch Bonereapers immediately emerged from their catacombs and conquered vast areas, especially in Shyish, the Realm of Death, from which their legions hail from.

But it was in the Eighpoints that Katakros military genius excelled. That place is the headquarter of Archaon the Everchosen and it was considered unassailable by anyone than the Ossiarch. In a rapid campaign Katakros managed to secure the Arcway, the Realmgate that connects Shyish with the Eightpoints and build the Arx Terminus, a fortress deep within the Everchosen territory.

Despite Katakros being defeated in single duel by Archaon, his soul returned back to his fortress to be remerged in the bodies built by his Mortisan for the occasion, and the situation is stalled since then, with Death having now a permanent stronghold in Chaos dominion.

The Ossiarch relentless war campaigns require a huge amount of bones to rebuild their ranks. Those can be of course retrieved from the defeated foes, but there are also other ways. All people conquered by them are requested to pay their tithe in bones to survive. It does not matter how they obtain them: from their own graveyards, self mutilation, sacrifices or fighting neighbour people. The only certainty is that not paying or cheating incurs in the Ossiarch legions wrath. And the bones will be collected one way or another.


Army rules for the Ossiarch Bonereapers

But how does a Ossiarch Bonereapers army play on a tabletop? First let’s go through the main rules for this army.

As always, the first option for an army is to choose its subfaction, for the Ossiarch those are called Legions and there six of them:

  • Mortisan Praetorians: comprise the loyal servants of Katakros, allows one charge in the enemy charge phase.
  • Petrifex Elite: nomadic legion expert in manipulating the most ancient fossils, subtracts 1 from wound rolls against Harvesters, Immortis and Stalkers (check the FAQ for the errata).
  • Stalliarch Lords: vanguard legion famous for their mastery of horse combat, allows re-roll charges of mounted units.
  • Ivory Host: set to conquer Ghur, they have been imbued with its primal rage, when injured in the same turn, they add an extra wound roll on unmodified 6s to hit.
  • Null Myriad: soldiers tempered with the most arcane death magic, on a 2+ can ignore spell effects when in range of a Mortisan or Arkhan.
  • Crematorians: a fiery legion prone to explode on death in search of an escape from their fate, they assign mortal wounds on death on a 5+.

Then we get to the main rules. First of all, all Ossiarch are immune to battleshock tests, have a 6+ after-save ward, and their Nadirite Weapons (only melee profiles and no mounts) score 2 hits on an unmodified 6 to hit.

But the core of using an Ossiarch army comes from their Relentless Discipline that provides them extra command points to use on abilities or Ossiarch Commands. The main difference with normal command abilities is that they can be issued multiple times in the same phase, as long as in that phase the issuer has not issued a command and the receiver hasn’t received one already. Here is the list of Ossiarch Commands:

  • Re-form Ranks: allows retreat and charge.
  • Unstoppable Advance: adds 3″ of movement in the movement phase.
  • Reknit Construct: heal or return slain models when not engaged at the end of the movement phase.
  • Counter-strike: adds +1 to wound when charged by an enemy unit and not already engaged.
  • Impenetrable Ranks: adds +1 to the ward roll for an attack.
  • Bludgeon: improves by 1 the rend of melee weapons.
  • Unflinching Coordination: a unit that has not fought yet can fight soon after the issuing leader.

Ossiarch have access to a list of command traits like Diversionary Tactics that reduces by 3 the enemy’s charge roll when in range of the general, Show of Superiority that has a chance to double the cost of command abilities and Mighty Archaeossian that allows to ignore negative modifiers on save rolls.

The list of artefacts of power include Lode of Saturation that increases the ward roll by 1 and Artisan’s Key that gives a Boneshaper the chance to use its healing ability twice.

Ossiarch wizards have also access to the Lore of Ossian Sorcery that we will be discussing in its specific section below.


Units and their roles in the Ossiarch Bonereapers Army

Heroes in Ossiarch Bonereapers

Heroes can perform Heroic Actions, in addition to the other abilities they can perform. You do it in the hero phase and you can only do one heroic action. Here is the list:

  • Heroic Leadership: on a 4+ (or 2+ if your general has been slain) get a command point only that hero can use.
  • Heroic Willpower: one non-Wizard hero can attempt to dispel or unbind a spell for that phase like he was a wizard.
  • Their Finest Hour: can be used only once by each hero to improve save and wound rolls by 1 for that turn.
  • Heroic Recovery: a disengaged hero can heal D3 wounds if he rolls less or equal to his bravery with 2D6.

The Great Necromancer, Nagash is available for any Death army and Ossiarch Bonereapers are not excluded, but we do have a separate guide for him.

Katakros, Mortarch of the Necropolis is the veritable leader of this army, literally given to him by his sponsor. While he is not a bad fighter, his main role is to lead the army, providing essential buffs, and when enough wounds are taken (representing his retinue being decimated), his attack profile becomes much more aggressive.

Despite being linked to Mortis Praetorians legion, he can now buff any legion, greatly increasing his use. He can issue a command ability for free per turn, heal Ossiarch units, increase melee attacks by 1 of a friendly unit, and add +1 to hit and save rolls of all Ossiarch units within 24″.

He can also hinder the enemies: preventing them from getting a command point on a 5+ once per turn, or reducing by 1 the hit rolls of a single enemy unit each hero phase.

He can be expensive but is definitely an improved version and can have a role in many lists.

While technically having been discorporated in his fight with the Lumineth, Arkhan the Black, Mortarch of Sacrament is a powerful caster. As Katakros, he also counts as a general even when not picked as first option, but where Katakros buffs combat units, Arkhan is there for magic prowess.

He is a triple caster with knowledge of the entire Lore of Ossian Sorcery and a casting/dispelling bonus that starts at +2 when at full health. He also increases the range of Death wizards spells around him by 6″.

He can heal Ossiarch units (same as Katakros) and his signature spell can slowly kill an enemy unit as long as you roll high in the first few tries.

Cost-wise it is prohibitive to have both Arkhan and Katakros in the same list, so there will be a choice to be made and either are great options to accompany your main general.

Arch-Kavalos Zandtos is the named version of the Liege-Kavalos, both options are available from the same kit. Zandtos is a powerful cavalry based hero, with damage on charge, the ability to issue a command for free every turn and an interesting command ability that gives +1 to wound to all nearby friendly units (can be used each combat phase).

While he is a good hero, the Liege-Kavalos can be further buffed and become an extremely powerful anvil with the right tools. As a general with the command trait Mighty Archaeossian, the artefact Lode of Saturation, receiving the command Impenetrable Ranks, and activating his Finest Hour can become 2+ save ignoring rend and 4+ ward without the opponent being able to stop it. There are replacements to the heroic action like Katakros command ability or the spell Mystic Shield. Speaking of spells, Reinforce Construct can bring the ward roll at 3+ but only against mortal wounds.

Apart from this, the Liege-Kavalos has the same damage on charge and free command ability per turn, but replaces the +1 to wound command ability with one that gives +1 attack in the next combat phase (it is issued in his hero phase).

Vokmortian, Master of the Bone-tithe didn’t see the table in his previous iteration, but is know a much better defensive tool. To attack him in melee on a 3+ the opponent has to use a command point, further more, his signature spell allows on a 4+ to remove a model engaged with him. On top of that he is a double caster with knowledge of all spells from the Lore of Ossian Sorcery, and reduces enemy bravery by 2 (or 3 if the opponent chosen general is dead) to all enemy units within 12″ (that nicely combines with battleshock triggering abilities).

Are those abilities enough to see him on the battlefield? Only time will tell, but you are forced to make tough decisions when list building with this army.

The Mortisan Ossifector is the last hero to join the army. He is there to support your Gothizzar, Mortek Crawler or Morghast. with an ability that gives one of this unit each turn either an improved rend (by 1), first wound/mortal wound negated each phase or exploding 6s to hit (they become 2 separate wound rolls) on missile attacks. His signature spells allows him to do it up to 3 times to different units.

The Mortisan Boneshaper is able to heal, and if provided the artefact Artisan’s Key can heal two units per hero phase. His signature spell is a horde thinner (1 mortal wound on a 5+ for each model in the target unit). Overall he is an interesting single caster healer.

The Mortisan Soulmason it the only one of his caste with a mount and a double caster with knowledge of all spells. But the main reason you are considering him is the fact that he can give +1 to wound to melee attacks to Mortek Guard or Kavalos Deathrider units. He can do it quite reliably at least twice, but on a roll of a 6, he can do it D3 times more.

When you have a so versatile roster of wizards, unavoidably you’ll have one that disappoints. This is the case of the Mortisan Soulreaper that counts as a single caster melee wizard, able to thin down horde units between his buffed up attacks (+2 against units of 5+ models) and his signature spell for 3 damage.

You have better melee fighters, and better wizards at the same cost.

Monsters in Ossiarch Bonereapers

Monsters can perform special abilities called Monstrous Rampages at the end of the Charge phase. Each action can be performed only once per phase therefore only up to 4 monsters can perform one at a time. Here is the current list:

  • Roar: on a 3+ an engaged enemy unit cannot issue or receive orders in the following combat phase.
  • Stomp: on a 2+ do D3 mortal wounds to an engaged unit that is not a monster.
  • Titanic Duel: + 1 to hit rolls against another engaged Monster.
  • Smash to Rubble: on a 3+ demolish a close-by terrain feature, disabling its scenery rules.

Apart from Arkhan the Black, the only other monster in the army is the Gothizzar Harvester. This giant bone construct has a missile attack, decent melee attacks but its main role is to bring back slain companions. Its ability has changed many times in the past, including an immediate FAQ that corrects its latest version, but now it works this way: at the end of the combat phase you choose a single unit that lost models in that phase.

For each model slain in that phase you roll a dice and for each 4+: if the original unit is injured, you heal them 1 wound if their wound characteristic is 4 or less or 3 wounds if they are 5 or more. The rest is a complicated way to say that you can bring back a slain Mortek Guard.

The changes simplify the rule but really challenge the utility of this piece, and the increased cost on Mortek Guard (it does not work on enemy units and in the shooting phase or other phases).

Battlelines in Ossiarch Bonereapers

The Mortek Guard are one of the main battleline for the army and the cheapest although still overpriced (the Kavalos have a better ratio point per wound). They receive buffs from all other abilities, are easy to heal back (although the Harvester has been nerfed considerably) and they are quite resistant with their own ability to make them “ethereal” (ignore positive and negative save modifiers).

That ability cannot be used in combination with other combat phase abilities but it is possible to give them the 4+ ward against mortal wounds from the Reinforce Construct spell or ignore their ability and bring them to 3+ with other save abilities against low rend units.

If taking a unit of 20 models or less, the blades are much more performant, but if taking a unit double reinforced (30 models) then the spear are more advantageous to allow the third line to enter combat.

The Kavalos Deathriders are the other battleline option, a mobile version of the Mortek Guard. They do damage on charge and they fly over screens in the charge phase (as long as those screen units have a wound characteristic of 3 or less).

They are extremely useful and with their +1 to charge from the standard bearer can be more than a nuisance if they charge in the enemy phase thanks to the Mortis Praetorians legion ability.

Conditional Battlelines in Ossiarch Bonereapers

The Immortis Guard becomes battleline if the general is a Mortisan. They are an anvil unit with a 3+ save and the ability to “bodyguard” a nearby hero (on a 2+ the wounds or mortal wounds allocated to a nearby hero are redirected to them). On top of this, they can once per game attack a second time at the end of the combat phase.

The Necropolis Stalkers are the other assembly option of the Immortis Guard and exactly as them, they become battleline if the general is a Mortisan. Where the former are the anvil, they are the hammer.

They can run and charge issuing themselves a command, and they can further buff themselves each combat phase with a +1 on hit, wound, save or damage depending on the occasion.

Morghast Harbingers with Spirit Swords

The Morghast Harbingers and Morghast Archai are the oldest models of this army, vestiges of Warhammer Fantasy late period. They are assembled from the same kit and both have the same identical weapon options: Spirit Swords of Spirit Halberds.

They both fly, shut down the issuing of command abilities to enemy units engaged with them and strike-first if the unmodified charge roll was 8+. As their rend can be improved in a variety of ways, and the engaged unit cannot issue All-out Defence, they are great to pick heavily armoured units.

The main difference between them is that the Archai have a 5+ ward when close to friendly heroes, while the Harbingers can be set-up in reserve to ambush in later phases. Swords are a bit more efficient than Halberds except on extremely poor save characteristics (6+ or none).

They both become battleline if the army includes either Nagash or Arkhan.

Wizards and Priests in Ossiarch Bonereapers

Despite the Mortisan caste defined “priestly” there are no priests in this army, and all Mortisan plus Nagash, Arkhan, Vokmortian and Mir Kainan, are all wizards with access to the Lore of Ossian Sorcery.

This lore has all great options, further incremented by a command trait like Dark Acolyte that allows the general to cast the first spell without allowing to unbind it.

Spells include Reinforce Constructs that provides a 4+ ward against mortal wound, Empower Nadirite Weapons that triggers the exploding hits on a 5+ instead of only 6s and Mortal Contract that allocates D3 mortal wounds to a unit at the end of each phase they damaged a friendly Ossiarch unit.

Arkhan, Vokmortian and the Mortisan Soulmason know all spells from the lore automatically. Arkhan is a triple caster that extends the range of other wizards by 6″, Vokmortian and the Soulmason are double casters, while the Ossifector, Boneshaper, Soulreaper and Mir Kainan are single casters.

Mir Kainan and his Reapers are a warband originally from Warhammer Underworlds, season 4. His particularity comes from his spell that forces an enemy to use its melee attacks against him. But if you ran out of combat? Tough luck, I guess they can’t attack until they can move next phase and kill him. On top of that, the Reapers can bodyguard him, absorbing the damage taken by the leader and they count each as 3 models when contesting objectives.

Other units in Ossiarch Bonereapers

The Mortek Crawler is the Artillery piece of the army. It has 3 different missile profiles that you can choose from when is your time to shoot but the best characteristic is that it can apply strike-last effect to the targeted unit. It can spread the malus across multiple units (each targeted unit on a 5+ strikes-last) but if the hits are concentrated on a single unit, it is much more reliable (it becomes on a 3+).


Endless Spells, Terrain and Value Added boxes in an Ossiarch Bonereapers Army

Ossiarch Bonereapers have the full set of endless spells, faction scenery and value-added box. The endless spells are all bonded, meaning they cannot be controlled by anyone than their summoner despite being predatory.

The Nightmare Predator is the classic damage dealer for D3 mortal wounds on any unit passed across or up to D6 to a unit within 1″ at the end of its movement. But the fun comes with the Soulstealer Carrion, that can prevent enemy units with a wound characteristic of 1 or 2 from contesting objectives within 6″ of the bird. Remember Dark Acolyte that allows the first cast spell to be impossible to unbind? Well this spell is a great way to use it and take over an objective.

But the best of the lot is the Bone-tithe Shrieker, with a 12″ range of -1 ward roll and no Rally/Inspiring Presence for enemy units… This is a good selection of endless spells.

The Bone-tithe Nexus is the faction terrain. It allows to dispense a punishment to enemy units within 18″ on a 4+ (or 3+ if enemy models were slain within 12″ of it the previous turn). The list includes no run and -3″ to charge rolls, -1 to hit, D3 mortal wounds or -1 to cast or chant to a wizard or priest.

Ossiarch’s value-added box is a Vanguard one with a Mortisan Soulreaper, 20 Mortek Guard, 5 Kavalos Deathriders and 1 Gothizzar Harvester. It is a good place to start this army, despite 2 out of 4 units being currently disappointing in the third edition, but the wheel turns and they are models you will need to complete your collection eventually. The other 25 models can make 3 different battleline units with the Mortek that can be taken as 2 individual units or one reinforced once.


Image from Warhammer Community

Tactics and Final Verdict on the Ossiarch Bonereapers Army

Ossiarch Bonereapers jump in the third edition with a battletome worth of this period. While they were struggling before, they are now at a comfortable position in the middle of the ranking.

Although they seem a bit overpriced, this can be easily fixed in the next General’s Handbook. The almost-day-one nerf that once again hit the Petrifex Elite and the Gothizzar Harvester rules is sad but unavoidable. Both rules are now easier to implement but, make both legion and unit not worth using except some niche lists.

Despite these small hiccups, the tome is solid, with plenty of options and only few warscrolls that can be dismissed. It still seems lacking some roles, like archers or skirmish units, but this should come in time with an expansion to the range.

The biggest questionis: with units so elite and therefore expensive in points, which leaders are you going to take? While you could create a viable list with both Katakros and Arkhan, that is a huge commitment in points that does not leave much place to other leaders. You can even work without either, but at least one seems a good starting place for the army.

You will need a Mortisan or two, maybe a Boneshaper for its healing abilities or a Soulmason for its buff to the battlelines (and the double caster ability). The endless spells are juicy, in particular the Carrion that can protect your objectives from chaff and the Shrieker that can be deadly for low-bravery units or armies that rely on the ward rolls. And don’t forget that Vokmortian can reduce further the bravery so that a combination with the Shrieker against most destruction armies or Skaven, can be deadly.

The spell lore in this army has all great options and with 3 wizards (4 with Nagash) knowing the entire lore from the onset of the battle, you can avoid struggling to decide which spells to equip during list building. Between the spells and the endless spells, your problem will be more how many wizards you can take to maximise the spells to perform each hero phase.

The only melee hero, apart from Katakros and the Soulreaper, is the Lieve-Kavalos that can be buffed in a variety of ways, especially if you take it as a general. Considering his mobility, it’s not a bad deal at all. He can follow-up either Kavalos or Mortek Guard and give +1 attack to them. These two battleline options are essential in an Ossiarch army. The right combination of them and their use will make the difference on the battlefield. While Immortis Guard and Necropolis Stalker have a defined role (anvil and hammer respectively), they are elite units with huge bases that will cover a limited portion of terrain. Where you want to spread your influence will be with Guards and Deathriders, with the latter a better wound-point ratio at the moment.

Of the units the last mention goes to the Mortek Crawler that is a nice artillery piece with a 36″ range on one of its missile profiles and the ability to apply strike-last effect before you commit with a charge.

Regarding the legions, there are 2 options that stand above everything else: the Null Myriad if you play in a heavy-magic meta and the Ivory Host for some serious damaging potential. The Ivory Host allows to score 3 hits for each unmodified 6 to hit on melee weapons (except mounts, but need to have been wounded in the same phase first) that, combined with the Empower Nadirite Weapons makes a unit double their hit on a 5 and triple on a 6. And this combines perfectly with all the +1 to wound bonuses in the army (Mortisan Soulmason, Zandtos or even the Counter-strike Ossiarch command when charged).

One final note goes to the Ossiarch commands and the new Relentless Discipline rules. You can now collect an absurd amount of command points to use on a vast set of abilities, including some heroes that can issue a command for free each turn (Katakros, Zandtos and the Liege-Kavalos). Some of our favourites are Bludgeon for an improved rend (that can be combined with the Ossifector ability to have -4 rend Morghasts…), Unstoppable Advance for that extra movement that Mortek Guard love and Impenetrable Ranks for that extra +1 on ward rolls. Without forgetting Katakros +1 to hit and save rolls within 24″ that is used in the hero phase and can be combined with other combat phase abilities, Zandtos +1 to wound within 12″ or the Mortek Guard “ethereal” command.

Overall Ossiarch 3.0 is back to its origin, a strong and solid army, maybe a bit overpriced at the moment but with a robust backbone, plenty of great options and only a few disappointing warscrolls. All while waiting a potential expansion of the range, that we can only hope will come sooner than expected.


Other resources

Some excellent information that we often use from articles like this one comes from YouTube channels like Warhammer Weekly with Vince Venturella, AoS Coach and of course The Honest Wargamer.

If you are interested in the competitive standpoint, when we talk about statistics, a tremendous effort is done by Rob from the Honest Wargamer, Ziggy and Tsports Network! in the AoS Stat Centre with precious information, constantly kept up to date.

Really good informative material is also collected by Dan from AoS Shorts.

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