A new weapon in the armoury of the Tau Empire, the XV9 Hazard Battlesuit close support armour is a sophisticated and powerful Tau Battlesuit that has remained something of a controversy both among the more traditionalist Tau Ethereals and elements of the Earth Caste. Though undoubtedly powerful, its armament is short ranged and the Battlesuit's systems are more complex than any that has come before it, requiring a veteran's skills to master its power in combat. Such is the complexity and demands of this Battlesuit that XV9s are only entrusted to veteran Fire Warriors of the rank of Shas’vre or higher when actively deployed on campaign. Those Shas'vre who has been assigned to pilot the XV9 Hazard Battlesuit are all XV8 Crisis Battlesuit combat veterans and survivors of deadly battles against the most savage enemies of the Greater Good. Nevertheless, it has proven effective on the various battlefields during the defence of the Tau Empire during its most recent Third Sphere Expansion.
The XV9 requires a huge expenditure in resources to produce in useful numbers -- resources some argue are better expended elsewhere building larger quantities of the more tested Battlesuit designs. The XV9 is a considerably larger Battlesuit than its more commonplace counterparts, such as the XV8 Crisis Battlesuit, and is built to the highest specifications that the Tau Empire can produce on a substantial scale. As well as greatly augmenting the warrior within, the XV9's built-in systems feature a powerful compact energy source that enables it to mount weapons, based on experimental technologies, of an unprecedented strength for its size.
Created with the goal of countering the growing alien incursions that threaten the gains of the Third Sphere Expansion in mind, the XV9’s battlefield role is focused on applying overwhelming firepower in relatively short range engagements against numerically superior foes. The XV9 performs this role admirably due to its possession of the greatest degrees of durability and mobility Tau technology can currently provide.
The results gained in service by the XV9 have converted many Fire Caste war leaders to its cause. In particular, the Fire Caste of the Ke'lshan Sept have mastered the use of XV9s both in conducting counterattacks and in using its potent firepower to prevent enemy advances. In doing so, the bulk of a mobile Tau Hunter Cadre is allowed to repeatedly redeploy into superior firing positions. This can prove a dangerous tactic for the XV9 pilots to execute, but for the solemn and determined Fire Warriors of Ke'lshan, it is a worthwhile risk in the service of the Greater Good.
- Swift Protector Wing - The Swift Protector Wing is a specialist deployment used in the most hazardous warzones, where some of the most sophisticated technology the Fire Caste has at their disposal must be utilised. Developed as a logical extension of the Fire Warrior counterstrike Cadres first advocated by Commander Puretide during the Imperial assaults on the Sept world of Dal'yth, the Swift Protector Wing was the invention of the hard-pressed Fire Caste of the Ke'lshan Sept. Made to take advantage of the newly issued XV9 Hazard Support Armour, the wing mounts a force of six of these advanced Battlesuits within a specially modified Orca transport to rapidly deploy them to the battlefield. The Swift Protector Wing allows a battlefront Tau Commander to swiftly redeploy a great deal of firepower to block breaches in his force's lines, or apply further pressure to a point of attack where the enemy line of battle teeters on the brink of collapse This dangerous duty is taken on as a matter of pride by the Shas'vre who pilot the XV9s, who view deployment in a Swift Protector Wing as a great honour and readily embrace the task of standing between their fellow warriors and harm. The formation's specially-modified Orca transport allows the XV9 teams on-board to deploy from it during a drop-run with a relatively high degree of accuracy. Additionally, the Orca's modifications and the skill of its pilots mean that it is able to be piloted as a skimmer. Orcas utilised to transport XV9s in a Swift Protector Wing are also fitted with nonstandard, defensive Energy Fields to better protect the transport and its occupants during operational strikes. A Swift Protector Wing may sometimes also be accompanied by a squadron of Remora Drone Stealth Fighters which provide further support in battle to the XV9 Hazard Battlesuit teams.
- Shas'O Vesu'r Ra'lai - Commander Vesu’r R’alai has become a legend amongst the grim Fire Warriors of the Ke’lshan Sept, and is one of the Tau Empire’s most experienced Battlesuit pilots. It is his leadership and innovation that has successfully led the way in the controversial tactics associated with the deployment of the XV9 Close Support Armour, one of which he currently operates. He is a strong advocate for the Fire Caste adopting more ruthless tactics against the Tau Empire's growing legion of deadly foes.
XV9 Hazard Battlesuits are fitted with several common features that all Tau Battlesuits possess. This includes advanced sensors built into its primary sensor cluster on the "head" which allow it to accurately detect enemies and provide detailed information on the battlefield and the current conflict’s status to the pilot. XV9s are also armed with the customary Tau Jetpack, allowing it to deploy from Tau transport aircraft such as the Orca and Manta (Note that an Orca must have a specially designed interior hold that can carry up to six XV9 Hazard Battlesuits). The Jetpack also grants the XV9 the mobility necessary to get its fearsome weapons into range at speed whilst providing a stable firing platform. The XV9 also makes use of special issue Vectored Retro-Thrusters incorporated into its Jetpack, allowing it to manoeuvre especially well, which is useful when the Battlesuit's pilot is trying to escape from combat. These thrusters also grant the XV9 the ability to perform the hit-and-run tactics that it is renowned for within the Fire Caste.
As a result of the Battlesuit's incorporation of a compact, high-capacity energy supply, the XV9 is able to mount prototype weaponry simply too powerful to be carried by a conventional XV8 Crisis Battlesuit, as well as more Battlesuit Support Systems than it would otherwise be capable of carrying. All XV9s are armed with two weapons from the list below as standard:
- Twin-linked Burst Cannons - These weapons are identical to the twin-linked Burst Cannons used by XV8 Crisis Battlesuits, and provide devastating anti-infantry firepower due to their withering hail of high-energy plasma.
- Phased Ion Gun - Developed from Tau Ion Weapon technology such as that used in the Ion Cannon, the Phased Ion Gun is similar to the experimental Cyclic Ion Blaster Battlesuit weapon system in that its rate of fire is extremely high and constant, although the strength of its ionisation effect varies due to the developing nature of the experimental technology. However, its energetic rounds are able to bypass virtually all forms of armour when the ionisation effect is at its peak.
- Fusion Cascade - Similar to the Fusion Blaster found on XV8 Crisis Battlesuits, the Fusion Cascade fires smaller, weaker bursts of Melta energy with a variable, but still high, rate of fire.
- Pulse Submunitions Rifle - An advanced variant of the Pulse Rifle, the Pulse Submunitions Rifle uses the same Pulse Weapons technology to scatter bomblets of plasma energy over a wide area. It is excellent against entrenched enemies, as it can bypass cover to strike at the enemies within.
All XV9s are also armed with a Blacksun Filter, which is an advanced optical system that enhances and magnifies a warrior's low-light vision whilst simultaneously filtering bright flares of light that could blind him in battle, a Multi-Tracker, a sophisticated fire control system that is mounted in a sensor node that assists Battlesuit pilots in engaging enemy threats by using multiple armaments at once, integrated photonic dischargers, otherwise known as Photon Casters, built into their superstructure which operate like Photon Grenades in that they blind and disorient any opponents that try to assault the Battlesuit. An XV9 can also be outfitted with one of the following additional Battlesuit Support Systems:
- Drone Controller - A Drone Controller acts as a hub for communications between an operator and a number of Drones. They give the owner the ability to make use of up to two Tau Drones per Drone Controller.
- Shield Generator - Battlesuit Shield Generators project cohesive energy fields around the Battlesuit that can deflect blasts and blows that would otherwise outright destroy the Battlesuit.
- Target Lock - A Target Lock is a specialised target acquisition system that enables the bearer to engage different targets from the rest of the squad.
There are two known variants of the XV9 Hazard Battlesuit that have been encountered by the forces of the Imperium of Man to date. These variants include:
- XV9-01 - The XV9-01 is armed with two Fusion Cascades, weapons that are similar to Imperial Melta Weapons.
- XV9-04 - The XV9-04 variant is armed with twin Phased Ion Guns.
- Imperial Armour Apocalypse II, pp. 58, 60
- Forge World - Experimental XV9 Hazard Battlesuit Rules