Tyranids: Warzone Octarius Leviathan review

Hey all, Danny from TFG Radio here, and today is a special day. Today, I get to talk about my truest love: The Hive Fleets. With the new Warzone Octarius: Rising Tide, we get a new codex supplement with Leviathan, and we get some new rules to augment our Synapse rules. Today, we are going to dig deep into the Leviathan supplement and see how one of the lesser loved Hive Fleets is now going to be a top bug. As always, be sure to check out Frontline’s Tactics Corner to learn what our prey is doing and how to adapt!

This is our first codex supplement, which seems like a way to add rules while we wait for a 9th edition codex, so let’s just dig in and see what we can see here. First, a note: You can use these supplemental rules for a Leviathan Detachment, but that doesn’t mean you can’t also have other Hive Fleet detachments. Also, in case you forgot, you still get Leviathan’s Hive Trait, which lets you ignore wounds on a 6+ if you close to a Synapse creature.

Warlord Traits:

Swarm Leader: In the Command phase, select one Leviathan Infantry, Beast or Swarm unit within 9”. Until your next Command phase, that unit rerolls all hit rolls.

For several editions, Tyranid players have wanted one thing consistently: rerolls.  Our codex has a smattering of reroll 1s, but a tried and true full reroll is pretty much non-existent outside of Hydra’s Hive Fleet trait.  This very much changes the math on a lot of builds, making some units like Devilgants or Hive Guard even more effective or making lesser used builds like Tyranid Warriors or even Raveners far more useful.  Swarm Leader is also just a foundation for several different combinations that can create some big leaps in efficiency and power, and since it works in shooting and melee, you really can have several different avenues for these combos although you really only get to trigger one per turn.   That is the biggest downside is that this isn’t a Guilliman style aura but rather a one and done, and it cannot target Monsters, but hey, it is still loads better than what we have.   This Warlord trait alone is worth switching over to Leviathan, at least for one Detachment. 

Strategic Adaptation: Before the first battle round (after deployment), you can redeploy two Leviathan units, including putting them into strategic reserves for no CP cost.

This is a fun one that is similar to what we already have but with the bonus to being able to put units into Strategic reserves.  This happens after the roll to go first, so if you are taking say Devilgants and are suddenly going second, you can put them into strategic reserve so they get to land their punch when they arrive.  You can also play defensively and put a big shooting threat like an Exocrine or Tyrannofex behind obscuring cover, or if going first, reposition them into an open firing lane.  Is it worth taking over Swarm leader? Hell no, but since you can have a Warlord with 2 traits, this could be a worthy second trait depending on your build, but this one is very much situational. 

Gestalt Commander: At the start of each battle round, select one Warlord Trait for the Hive Fleet Warlord traits in the Codex and gain that trait, replacing all keywords with Leviathan.  You cannot select Perfectly Adapted or any Warlord trait that a model in your army already has.

This one has some moves in the sense that it allows you to somewhat customize your needs on a turn by turn basis.  The issue is that the Hive Fleet specific warlord traits aren’t exactly money in the bank, but they do provide a lot of corner case plays, and for a savvy general, that can absolutely matter.

Hydra is great for healing up your warlord, especially on a chonkier body like a Tervigon or Hive Tyrant. Kraken is good for any fighty Warlord as fighting first is always a good thing and can really mess up an opponent’s plans if they have multiple charges in one turn.  Jormungandr is great for a shooty list as being able to ignore cover can really matter since a lot of our weapons have poor AP, and against a psyker heavy list, the Kronos warlord trait can absolutely cause some havoc, especially if you also take a Kronos detachment for access to the Deepest Shadow.  Again, this one really does depend on the general, but it has a very low skill floor, so if you don’t leverage it well, it is a bit of a wasted opportunity. 

Overall, these Warlord Traits are generally better than anything else Tyranids have outside of sacrificing a WL trait for another Adaptive Physiology.  Really, Swarm Leader is the auto-take, and whether or not you want 2 units with Adaptive Physiology or not is up to you and your build. 


Biomorphic Carapace: Subract 1 from Wound rolls against the bearer.

This is a solid relic if you are taking a Monster Warlord.  Really, it helps keep a Tervigon, Maleceptor or Hive Tyrant alive a lot longer, especially a Tervigon with Gestalt Commander who can start healing up wounds.  At T8 with a 5++, the -1 to wound means that lascannons suddenly fail on 4s and meltas fail on 5s, which is pretty tasty.  That extra 16% survivability certainly helps.  If you really want to run a Tervigon based build, this seems like a mandatory relic and worth it for a CP to purchase alongside Resonance Barb.

The Void Crown: Psyker only. The bearer knows 1 additional power. It can attempt to use 1 power in the same phase that it performs a psychic action.  If the bearer makes a pyshic test of 9+, the power/action cannot be denied.

This one is very situational, and if you are building a list where say a Neurothrope is going to be going for a psychic secondary, it makes sense as they can still put out buffs or what not.  This is not really one that you should be prime to get unless you are specifically building a list where you know you can max or close to max all 3 secondaries you choose.  If I was doing a horde style list that was more about board control than sheer damage, this is something I would consider.

Synaptic Hive Blades: Boneswords/Monstrous Boneswords only. The bearer’s melee attacks with Boneswords/Monstrous Boneswords ignore invulnerable saves.

This sounds so cool, but the reality is that Boneswords are not good.  The very best you get is 5 S6 AP-2 D3 attacks, which certainly isn’t horrible, but the -2 AP means that your opponent is still getting their armor save, so unless you are going against Daemons or Harlequins that rely entirely on Invul saves, this really isn’t that amazing.  I suppose if you really want a fighty threat out of reserve, an Adrenal Gland Flyrant with these can maybe do some decent damage to a single target, but even against Deathwing knights, they are still saving on a 3+ thanks to Stormshields.  If Boneswords get a rework in a later publication, then maybe these come into play.

Adaptive Neural Lobe: While the bearer is on the battlefield, each time your opponent spends a command point, you roll a d6 and on a 5+, you gain 1 command point.

Tyranids are a CP hungry army, naturally, so having some CP regen is a damn good thing.  Seeing as how just about any Tyranid build is going to want to spend 2-3 CP a turn at minimum, maybe even more depending on other factors, being able to regen some of your expenditures keeps you flush with CP for longer.  Generally speaking, you really want Resonance Barb, so you have to spend the CP to purchase this, but it should pay for itself over the course of the game.  This is definitely a strong contender for second relic, and if you are building a list that doesn’t rely on psychic powers, then I could see forgoing Resonance Barb entirely for just this.  Especially as Leviathan has so many awesome strats, you are going to want every single CP you can get.


Relentless Fury: 1/2CP.  Use in Shooting or Fight phase. Each unmodified Hit roll of a 6 scores 1 additional hit (2 if the unit contains 11 or more models). If used on a Genestealer unit, this costs 2 CP. 

There are just levels to this one, man.  In the Fight phase, it really ups the damage potential of our infantry. Getting Hormagaunts to have “tesla” style melee attacks really makes up for their S3, and if you can get all 30 into combat with 60 attacks, that’s 58.33 expected hits when factoring in reroll 1s from the talons and 2 extra hits per 6.  That’s a big boost in overall output, all for 1 CP.  Of course, you can throw it on Genestealers for 2 CP for even more punch, which Genestealers actually need.  While they throw a ton of attacks, they tend to stumble in the era of 2 Wound infantry and super tanky units, so getting them more hits means more chances to roll those 6s on the wound.  Of course, if you Swarm Leader the unit, then you can really, really get some extra hits here.

But let’s not forget that this works in the Shooting Phase too.  With this, you can run double Hive Guard with a ton of efficiency.  Your Leviathan Hive Guard get an extra hit on the 6 to hit, if combined  with Swarm Leader, you can reroll to fish or just balance out a bad roll, and you can still have a Symbiostorm’d Kronos unit doing the exact same thing, and one of them gets to shoot again thanks to Single-Minded Annihilation.   That’s a ton of high quality, ignore LoS, ignore cover shots that can absolutely murder targets and still keep the Hive Guard out of danger.  You can also throw this on Devilgants or even Deathspitter Warriors, so if you don’t need the power of the Hive Guard but need volume, 90 shots that turn into 75 expected hits or 112.5 expected hits if you Swarm Leader them, Devilgants become pretty terrifying. 

Questing Tendrils: 1 CP. Use in your second Movement phase when setting up a unit from Strategic Reserve. They can enter the board as if it was battle round 3.

This is very much a low floor, high ceiling strat that really works if you build for it.  Being able to have more freedom to walk on from the board edge can have big gains, especially if combo’d with Strategic Adaptation for putting 2 units into reserve for free.  Making sure Devilgants arrive on the right flank or even bringing out a melee threat to counter a backfield rush can do some good work.  I don’t know if you are going to use this Strat every game, but it is very much nice to have. 

Alpha-Leader Beast: 1 CP. Use during roster building. Your Warlord gains one additional Warlord Trait from the Leviathan table.  You cannot duplicate Traits.

This is just a great tek piece that allows you to either double up on the great Leviathan warlord traits or take an extra adaptive physiology and then purchase Swarm Leader. Unless you are building a list that doesn’t need any adaptations and really just want Swarm Leader, there is not a lot of good reason to not use this strat. If nothing else, taking Swarm Leader and Strategic Adaptation is a solid combo. 

Animated by the Hive Mind: 1 CP. Use when a non-Titanic Leviathan Monster dies. Their explosion is triggered automatically.

This is a great corner case strat that is unfortunately not as synergistic as it could be.  While you can do Leviathan Monster-Mash (I love the 6+++ Feel No Pain on Tyrannofexes and Barbed Hierodules), a lot of the sheer power in the Leviathan supplement is for infantry more than anything, so big beasties don’t get the full attention.  Still, being able to just explode when you want is awesome for sniping out a wounded character or polishing off a wounded vehicle, and heck, cascading explosions are certainly possible (just ask Salty John).  Again, this is very much a corner case strat, but I think most Leviathan builds are going to lean into infantry over monsters.

Synaptic Domination: 1 CP. Use in Psychic Phase. Select one friendly Leviathan Synapse unit and one friendly non-Synapse Leviathan Unit. Until the next psychic phase while the selected Synapse unit is still on the battlefield, the non-Synapse unit counts as in range of Synapse.

This is a cool strat to help with surprise, out of reserve, tricks.  One of the downsides of our infantry is that if they are not supported, they melt in morale, but with this, you can bring on a Devilgant unit or even Adrenal Gland Hormagaunt unit out of reserve on a far flank, and not have to worry about any Synapse issues for the turn.   It can also help with a Swamlord and Genestealer Slingshot as the Genestealers often get way out of Synapse, and you want them to stick around as long as possible, so ignoring Morale for them is key.   This is definitely one to remember, especially if either doing a sling-shot list or an out of reserve list.

Control the Swarm: 1 CP. Use when a Leviathan Warlord is destroyed.  Designate a new Warlord (Synapse Character) with a new, unique Warlord Trait.  For mission purposes, your Warlord is not destroyed.

This is great if you are building a list designed to max secondaries and deny your opponent points.  Tyranids can be relatively character heavy, so Assassination can be a good secondary against us, so this can help mitigate that to an extent.  Still, there are not a lot of mission specific scenarios where killing the Warlord is important, so that diminishes this to some extent. If your opponent does take a secondary that involves killing your Warlord, you can mess with them quite a bit. 

Hive Mind Imperative: 1 CP. Use in command phase. Select one Leviathan unit within 12” of a friendly Leviathan Synapse unit.  Until next Command phase: the unit gains Objective Secured. If it is already had Obsec, each model counts as 2.  The unit can still shoot and perform an action. 

This is again all about the infantry, and it adds just a bit more to a control-style horde build where you flood objectives with bodies.  Being able to get 30 Termagants to count as 60 models essentially means you own an objective, and it even allows them to perform an action like Retrieve Octarius Data and still contribute some damage.  It also goes great on Hive Guard who are often holding down a back objective, so they can also score you an action and still do what they do, and if going against an army like DE that can throw small obsec units all over the place, being able to counter that can pay huge dividends.  Never forget this stratagem exists, ever.  It can easily win you a game where your opponent overextends to try and deny you primary points, you can cut them off at the pass, so to speak.

Hyper Adaptation: 2 CP.  Use in Command phase. Select one Leviathan Unit. It replaces the Leviathan Hive Fleet adaptation with one from Codex Tyranids.

This is a really fun one, and remember that whole double Hive Guard thing? Well now both get to reroll 1s to hit in shooting since you can swap over the Leviathan unit to having the Kronos trait.  Oh, you want to Swarmlord and Genestealer rocket? Well, now the Genestealer’s get their full 3d6, choose the best, advance.  Oh, you decided to go heavy on Hormagants and got them into combat to pop Relentless Fury, well now they are Hydra and reroll hits if they outnumber their target.  If you know you’ll need a longer charge and need some help, select Behemoth.  Heck, you never know if you need reroll 1s to wound in melee as Gorgon.  This is absolutely awesome, and really, this one stratagem lets you build a pure Leviathan list while also cherry-picking the best tactics from other fleets.  Yes, you don’t get the stratagems, but being able to build a list that can do several different surprises is never bad.  This is definitely a marquee strat for me and one of the main reasons to take Leviathan now. 

The Void in the Warp: 1 CP. Use in your opponent’s psychic phase after an enemy psyker successfully passes a psychic test and after any Deny attempts.  If the enemy is within 24” of a Leviathan Synapse unit, the power is denied on a 4+.

This is corner case, but it can be a big case.  If you absolutely have to deny a power, this gives you the chance to deny and then another 50/50 shot at flat out stopping it.  Some armies live and die on a key power going, so being able to have good odds to just stop that is legit.  Of course, this doesn’t always matter against some opponents, and it isn’t going to stop smite spam, but if there is just that one power (like a redeploy) that you absolutely need to stop, here is your chance.

Bio-Adapted Borer Grubs: 1 CP/2CP. Use in your shooting phase. One Leviathan unit using a fleshborer or fleshborer hive deals 1 Mortal wound for each unmodified Wound roll of 6 (max 6 mortal wounds). If the unit is a tyrannofex, costs 2 CP, otherwise 1 CP. 

This is a good way to make Fleshborer Hive Tyrannofexes more relevant, and well, 170 points for that much beef isn’t bad, now with a chance to do up to 6 Mortal wounds to really make those shots sting, it really isn’t something I’d rely on too much.   I actually like it more on Termagants as the standard, 5 point Fleshborer Termagant sure is humble, but being able to get some surprise damage output from them can be clutch.  Especially since you can Swarm Leader them for a full reroll to hit, you may only be getting up to 30 shots at max, but with the reroll to hit, you are getting more actual wound rolls (with a reroll 1s on it) than with a double-shooting Tyrannofex.  This is enough heat to kill a lighter target or even a character that thought they were safe from any “real” threats.  I don’t think I’d build around this at all, but it is a stratagem to keep up your sleeve. 

So, is the Leviathan Supplement good?  Yes, very clear yes.  It is the most flexible hive fleet for Tyranids, if you have the CP to pop the right stratagems, but really it comes down to a few standout winners that should absolutely dictate list design:

Swarm Leader.  This is just so much money, and it combos with so many different threats.  While Kraken has far more speed, getting just one unit to reroll is so important, especially since Tyranids excel at sending one really effective unit into the fight at a time.

Hyper Adaptation.  Being able to essentially turn one unit into either a Kraken rocket or a Kronos battery is just awesome, all while having other great abilities around like the 6+++ Feel No Pain.  At least in the first turn or two of the game, you are probably going to use this, and it really does allow you play a pure Leviathan force without sacrificing too much one way or the other.

Relentless Fury is just so good. It adds so much offensive power, and honestly, sometimes we need that. It makes any of our Infantry that much scarier both in shooting and melee, and I’d be hardpressed to think of an army build with Leviathan that didn’t lean into this at some point. 

Adaptive Neural Lobe: For me, this is essential for Leviathan because you are going to spend CP, and being able to regenerate some of it when your opponent uses theirs is going to keep you in the game longer.  If I have any critiques of Leviathan, it is that they really rely on stratagems, so being able to get more CP back during the game is absolutely, 100% essential to success.  There are definitely a few builds that I have already worked up that don’t take Resonance Barb and instead only take the Lobe.  In most games, even with a mixed army, I’d still pay the extra CP to get access to it as chances are, it’ll pay for itself and more. 

So there it is, a great new way to play Tyranids.  I really enjoy this new supplement because it can add to existing armies in some ways as well as open up entirely new lists with new styles.  While it is not legal for SoCal 2021, I cannot wait to start playing games with it, and hopefully I’ll get another chance to play in 1 more large event soon to really see how it does.   Stay tuned because I haven’t even talked Synaptic Imperatives yet, and well, there’s plenty of goodness in there too.  Thanks as always for reading, and as usual: play games and be nice to each other.

And remember, Frontline Gaming sells gaming products at a discount, every day in their webcart!



About Danny Ruiz

Long-long time 40K player, one of the original triumvirate of head 40K judges at LVO, writer, educator, tyranid-enthusiast, disciple of Angron, man about town, afflicted with faction ADD.
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