Editing Sky Serpents (section)

==Legion Tactics==
The legion specializes in hit and run tactics and mobile warfare at the operations level. Legion strategy places a great deal of importance on information, so as to know how best to draw out and achieve local numerical superiority to crush and disorder the enemy. Once a breach in the lines is achieved, Xun Tohilcoatl prefers an aggressive stance, so as to prevent the opponent from regrouping.
The legion is noted for its cohesion and ability to coordinate effectively with human auxiliae, as well as a high degree of technological proficiency, following its primarch's intense interest in technology, and as such, much archaeotech and armor is employed.

===Auxiliae===
====Legion Auxilia Section 8====

Section 8 is a the elite of Sky Serpents Auxiliae. They are specially trained for observation and disruption work. They prepare the ground for a Sky Serpents invasion, and, following the Heresy, have been used as a stay-behind force on more than one occasion.
Section 8 squads are infiltrated onto enemy worlds by a number of means, ranging from covert drops to the more common, if less dramatic, falsified documents. Once on the world, members of Section 8 prepare the ground for what is to come. Depending on their assessment of vulnerabilities and the projections of the Legion Command, Section 8 may be variously tasked with operations such as sabotaging infrastructure, generating social unrest, hiding supplies for legion operations, preparing ambushes, setting up locii for teleportatiin strikes, and general recon.
Once an attack is launched, Section 8 is often employed to spread confusion, be it through false reports, spreading rumors and panicking populations, or unleashing fire from previously hidden positions to support the landing.

It is said that Section 8 was introduced to the legion after Xun campaigned alongside [Redacted], though if this is so, then all records of it have been erased.

====Thule Rime-Guard====
Thule IVc 'Nanuk' is a cold world of frost-rimed stone beaches and snow covered pine forests in orbit of a blue-tinged ammonia gas giant, Thule IV. Nanuk is primarily involved in the production of krill and support for the refinery operations on Thule, as well as providing the core and training for the Rime Guard regiments. These form the core of the Sky Serpents Auxiliae Air Cavalry. The pilots are recruited from the transport pilots of Thule Station, while the jump troops themselves are drawn from rig workers and the ice raiders. When the Rime Guard deploy in support of the legion, pilots trained to fly in the storm winds and ring systems of a gas giant launch en masse to screen legion operations. Since the unaugmented human pilots cannot hope to match, or even survive, the maneuvers of the Astartes, they are equipped with slower craft which emphasize durability over speed, with craft such as Thunderbolts, Valkyries/Vendettas, and the Marauder class bombers. Through numbers and durability, they are able to make up for their lack of speed. During landings, these air support squadrons can be called upon to provide additional firepower, strike targets, diversionary or outside of the legion advance. In addition, infantry squads can be deployed to fortify landing zones and support legion advance.
These squads are traditionally equipped like Solar Auxilia regiments, but with additional provisions for air-dropped heavy weapons and lighter armor variants for drop troops.

====Sobek Fusilliers====
The Sky Serpents have never been much for static engagements. This task they delegate customarily to their human Auxiliae. As a result of this practice, there are numerous mortal regiments geared for garrison duty and long, grinding sieges.
Among the most famous are the Sobek Fusilliers. The Sobek Fusilliers are organized into paired companies, infantry companies and artillery companies. The infantry companies are universally equipped with lasrifles and flamers, but their most potent tool is their entrenching shovel.
They make planetfall with prefab defense lines, but once these are set up, the Infantry get to work digging and constructing a system of trenches which will serve as the basis for more complex defense works.
The artillery companies, meanwhile provide cover with relentless bombardment even as their guns are set in protected emplacements. The guns themselves run from rapier mounted field guns, to heavier mortars, up to weapons such as the basilisk and Medusa seige guns and beyond.
The Sobek Fusilliers have a sizable Mechanicum contingent, extending beyond the usual enginseers. Instead, techpriests of Orders Macrotek and Reductor are placed throughout the forces.
Typically, one of the two consuls is a Magus.
This is to ensure that the fortifications constructed are up to mechanicum standard and that the enemy position is levelled with optimal efficiency.
At times, this mechanicum oversight can also mean that heavier and more arcane weapons are brought to bear, including the holy Ordinatus Engines.
Under most circumstances, the Sobek Fusillier Infantry companies adopt a defensive posture. Not for them are the human wave assaults of some similar forces. Instead, they try to get the enemy to come to them, luring them into an assault with false weaknesses and crushing them. Not for nothing is their sigil that of a crocodile.
This said, the Infantry is perfectly capable of assaults, though  the bloody task of mass assaults is usually left for forces such as the Argon Apemen penal legions.

Another common practice is to use the Sobek Fusilliers to draw out or focus an enemy assault, allowing forces of the Sky Serpents to strike elsewhere.
Oddly enough, but perhaps characteristic of the impact of Jade Empire propaganda, this sort of mission is seen as among the most honorable. Because of the nature of such things, the Sobek Fusilliers seldom are told before hand that they are to be a distraction force, so naturally, they assume that honor is theirs.
To the soldiers of the Fusilliers, they are partaking in an age old rite of the mortal warriors, serving the Empire and legion with their steadfast defense just as the human troops called up by Songkulkan during the People's War allowed Xun and the Legion the time they needed to honor the Emperor and thrice-Sainted Faustus by rescuing Malcador and the other legions and buying time for Xun to return and slay the foe, as the legion always will.
Thus the glory of the people and the proletariat is to serve where needed and to stand fast.
They're sort of the logical extreme of the Jade Empire propaganda 'proletariat shield' idea. They have conviction that their sacrifice allows the semi-divine Legion, potentially acting through human regiments like the Thule Rimeguard, to do what it needs to do and through their steadfastness, they reenact the holy actions of the virtuous proletariat of Songkulkan's day. It lets them emulate Faustus, who stood fast on Luna. Just as Faustus told Xun to return to his people and that he would martyr himself to ensure the Emperor's ascension, it is their duty and right to be martyrs to let the legion serve the Empire. (Faustus said no such thing and Xun doesn't say he did. Nor do the scholar-bureaucrats and Legion believe any such thing. But you try telling that to a prole.) 
Of course, having walls to hide behind and big guns does nothing to harm morale.

===Armory===
The Legion's tactical doctrine of swift encirclement and mobile warfare means that mobility is highly valued. To this end, nearly every squad is assigned a dedicated transport of some sort, with these vehicles being preferred over jump packs or bikes. Most commonly, this is the rhino. (When the Razorback becomes available, Xun falls in love with it. Volkite razorbacks.... mmmm...)
However, the legion is also well stocked with Land Raiders and Spartan Assault tanks, preferring the latter for deployment of 20 man despoiler squads.
Another common means of transportation for 20 man despoiler squads is the Storm Eagle.

Squads are deployed in notional units of 20, the number of completeness in Tepectitlani culture. When deployed by rhinos or other such transports, the two squads of ten then support each other and fight as one.

The chapter is known for its deployment of armor, preferring Malcadors, Sicarans and Predators over the much slower legion artillery. When Vindicators are deployed, they are usually fielded in a stripped down configuration to allow for greater speed. (Like how Alpha Legion fields them in Book 6)
To augment this arsenal, the legion also makes use of aircraft such as the Fire Raptor.

In the legion's thought, the airborne infantry and weaponry are the Fangs and Fire of the Serpent, to snap out of nowhere and deliver a killing blow. (The teleportarium deployed terminators also fall into this category) The tanks and mounted infantry are the Coils and Claws of the Serpent, confining and disembowling the enemy.

The Legion shows a marked fondness for Volkite weaponry, and devotes a great deal of effort to maintaining and producing the otherwise arcane weapons. This is because the legion sees Volkite weaponry as an idea solution to the problem of how to deal with foes with extensive numerical superiority. Because the legion's deployment is mobile, it runs the risk of being cut off and unable to take a defensive posture. Volkite weaponry has the range and destructive capacity to hold off a foe while the legionaries dig in.

The exception to this general mode of deployment is seen in specialized linebreaker formations, which are generally held in reserve until the killing blow is to be struck. This is where the legion fields its Mastadons and Typhons and Dreadnaughts, as well as terminators and breaching units.

Psykers are relatively common in the legion, and are deployed as widely as possible. I'll type up a bit more later, but basically they do scrying on the enemy and communicate with one another to enhance cohesion in addition to killing yaks at 500 yards with MIND BULLETS. So how the Storm Seers of the White Scars are Chaplains + Librarians, these guys are Vigilator/Master of Signals + Librarians.

Basically, if we were to write up crunch, they'd have a unique consul type for them--still working on the name.
They might even have a rule like the Word Bearers Burning Lore or be able to upgrade a Praetor to a psyker for XX points like an Iron Warriors War Smith.

They'd probably have a rule to upgrade a tac squad to volkite for XXX points as well. And probably their LA rules would include scout. Really, it would probably look a lot like the White Scars with a provision that their compulsory troops must have DCs.

Likely in this universe, it's the Sky Serpents that invent the Damocles, which will have to get a cool Mesoamerican or Chinese sounding name.

While I'm at it, I'm thinking there's an elite terminator guard, that I'm oh-so-cleverly thinking of calling Jaguar Warriors. I'm imagining that the legion as a whole makes widespread use of glaives and macuahuitls, and these Jaguar Warriors would have a volkite in one hand and a macuahuitl in the other, and probably rad grenades/rad missile launchers, since these guys are for breaching and storming the gap.

I also imagine that they make widespread use of modified destroyer squads, since their weapons provide a means of compensating when outnumbered. They'd seldom use phosphex, but make use of rad weapons and maybe flamers or better, those mechanicum rad cleansers.

In a similar vein, they'd probably be fond of Lightning guns, but that's mostly for the visual and symbolic effect, rather than any strategic benefit.

So I'm thinking that they're distinct from the Angels of Light in that the Angels do much more jet-bikes and straightforwards assaults, from the Behemoth Guard in that they are heavy armor and nasty weapons straight to the face partying like it's 1916, from the Second Sons in that they aren't nearly so "dirty" with their weaponry, from the Warhawks in that their air cav is part of a two pronged approach with their ground forces and the focus for the Sky Serpents is 'confine the enemy with speed and confusion and then hit them like a ton of bricks' rather than 'ambush from ten sides', the effect is similar, but for the Sky Serpents, confusion is the weapon and speed is a good way to achieve that, and from the Fists of Mars by not being cyborgs, but I don't know enough about what they fight like to really go further.