[He hasn't been given a name yet so i have inserted _underscores to hold the place where the name should be entered.]
Imperial Guard, Lord Marshal _, born of Terra, is posted with his fleet in the Ultima Segmentum to slow the Tau expansion.
A long time spent fighting and learning the ways of the Tau doesn't go unnoticed and he is soon trained and indoctrinated as an Inquisitor of the Ordo Xenos.
Now, Inquisitor Marshal _, his unparalleled knowledge of the species turns to intrigue and quickly spirals into obsession.
During a short term at home on Terra he spends time with an old friend who is serving a period as Inquisitorial Representative. The friend finds his behavior concerning but as a final act of friendship and due to a sense of loyalty he simply arranges for him to meet with The Speaker for the Chartist Captains. The Speaker seems wary of engaging in conversation but offers a Warrant of Trade before dismissing him.
There are only two personal conditions of the Warrant issued. Firstly, the boundaries of his jurisdiction are Tau airspace and the surrounding areas. Secondly, he must aid in policing the Underhives of the Segmentum Solar. The latter condition is soon embraced by the Marshal as a perfect method of training his recruits.
_ slowly integrates himself with the Tau and begins recruiting individuals to work in all parts of his fleet and armed forces. To ensure their is no animosity between species he commands there be at least two Tau recruits in each unit that are sent to the Underhives.
His interest in Tau technology eventually leads him to upgrade most of his Imperial Sanctioned tech.

----------------------------------------------------------------------------------------------------

The individuals sent to the Underhive receive, arguably, the best training in the galaxy although they don't all come out alive, if at all. They go in as individuals but those that come out come out as a unit with a bond that cannot be broken. Not only do they have to contend with and purge unruly gangs and outlaws but their Tau companions put the entire unit in the firing line of any other policing force they encounter. If they make it out they are prepared for anything. To add to their problems, they are only issued with Imperial weaponry and low level Tau tech, this includes a flight suit which doubles as armour. This isn't due to a lack of Tau resources or the risk of losing expensive weaponry but simply that it would make it far too easy for them. Each unit is expected to complete a few random objectives, often delivered to them while they are already in the Hives, and most importantly they have to try and survive until they have served their full time. Anyone who manages to exit early will be turned away on return to the fleet or, often, simply killed for disobedience.

Thanks, man! Still nae batteries but all nine models are finished,