As Shogun of Shadows is an AU rp, there have been some change made to the canon to give us more of a blank canvas to work with. I haven't really nailed down a precise timeline or point of divergence here; partly because I want to leave room for you all to collaborate on fleshing out the world with your own clans and history as you create your characters and explore the world. The other reason is that its a lot of work and I'm feeling lazy. So. It's probably most helpful to say the shinobi world has largely developed along similar lines but by the efforts of different hands. No canon characters have existed in this version of the naruto world after the exploits of Madara Uchiha and Hashirama Senju. The jinchuriki exist, but may have had different experiences and met different people to the point that they might have entirely different personalities. Particular clans or groups that existed within the canon may still exist within this timeline, but they don't need to necessarily have had the same kind of history, if you decide to incorporate those elements into your character we can kind of play around with them and establish something that works for our needs.
With that out of the way, it might be helpful to now look at the general state of the world at the point where our story takes place.
the Shinobi world
Prior to the invasion that has so completely upended it, the shinobi world and its five great nations were in a state of balance if not quite peace. All five of the great nations were considered roughly equal in terms of military strength and they even controlled an equal number of the strategically important tailed beasts: two each, with the exception of Konohagakure, who made up the shortfall by controlling the ninetails, generally considered to be the most powerful of the fearsome creatures.
Prior to this point there had been three major conflicts worthy of the name "shinobi world war", only the most recent of which occurred in living memory. The third shinobi world war, also known as "The war of disputed succession" and sometimes privately "The Daimyo's war" Began when the Daimyo of the land of fire died and several influential nobles from different countries attempted to claim the throne through a complex web of blood and marriage relations. This war was generally unpopular with the leadership of the various hidden villages, who saw it as strategically reckless or with the rank and file shinobi, who generally saw it as a naked attempt at self enrichment by a few greedy nobles. Although the war was long and bloody and sowed the seeds for several long standing grudges, it also saw the development of a subtle sense of commiseration and comradery among the shinobi of all five villages. At many points during this war unofficial truces or negotiations took place to allow for events suchs as prisoner exchanges, or ceasefires to recover and bury the dead. Individual Jonin developed quiet back channels for communicating with their counterparts in enemy villages.
After the Third war ended, this informal back channels were often used to de-escalate flare ups of tension or conflict: several situations which might have lead to full scale war were instead able to be quietly resolved, leading to a prolonged period of relative peace, although it was not a peace without rampant espionage and clandestine violence of course. Imperfect as it
The Enemy
The force invading the shinobi world calls itself "The Army of the Shadows" Seemingly in reference to their leader, the self styled "Shogun of Shadows" a figure they appear to regard with fanatical loyalty and devotion. Precious little is known about the Army of Shadows, but careful observation and inference has produced a number of important conclusions.
The army of shadows is made up of a combination of shinobi, who seem to act as officers and special forces, and regular people who act as foot soldiers. Although unable to utilize chakra, these soldiers are heavily armed, armored and well trained and should not be underestimated, especially in large numbers.
That last point is especially key, as the Army of Shadows almost always operates in large numbers. Though the basic unit of the army is a twenty man squad (shinobi officers and eighteen foot soldiers) these squads rarely operate alone, preferring to deploy anywhere from half a dozen up to hundreds of squads for large scale operations like the invasion of Kirigakure.
The basic equipment for a foot soldier of the Army of Shadows is a spear, a short sword and a crossbow with various kinds of ammunition such as explosive bolts. Their armor consists of high quality, steel plate that offers full body protection and reasonable mobility. Underneath these plates is a kind of body suit of rubbery material of unknown composition that seems to have insulating properties, providing limited protection from heat, electricity and poisons. To complete the outfit each soldier has a helmet with a basic filtration device. The Army of shadows foot soldier is thus a surprisingly resilient target for many varieties of ninjutsu, they can be killed through such means, but it often takes larger commitments of chakra, time and risk than most shinobi expect it to and under the right circumstances they are easily capable of killing shinobi through heavy volumes of crossbow fire, explosives or surrounding them and wearing them down with spear work.
The fact that the army of shadows is both large and well equipped points to the conclusion that they are the armed force of an extremely large, wealthy nation: perhaps an empire the likes of which the Shinobi world does not have. Since seizing the ports of Kirigakure, the strange metal ships of the Army of Shadows have continued to ship in more reinforcements and war material, meaning we have not yet witnessed the upper limit of their size and strength.
The State of the War
At present, the war has gone extremely poorly for the allied shinobi villages. Kirigakure fell almost overnight and the Army of Shadows was able to swiftly advance from there to threaten konohagakure in a matter of months. As of the start of the rp, Konohagakure has also fallen in the aftermath of the disastrous battle of Hakari ridge, wherein allied forces were forced to retreat en masse after the The Army of Shadows used a combination of overwhelming numbers and unusual, chakra powered weaponry to force their opponents from the field.
There are some silver linings however. Allied casualties have been surprisingly low as the bilk of the Army of Shadows are foot soldiers, they are not well suited to chasing down fleeing ninja, who have largely been able to disengage safely and rejoin their allies to fight again. This was especially evident in the fall of Kirigakure, which in large part happened so quickly that many key shinobi were unable to return to the village from their deployments and missions before the village fell. These shinobi were nearly all able to move into the land of fire and join up with alllied forces ready to fight and the same was true for shinobi from all villages after Hakari ridge thanks to the heroic sacrifice of a small rearguard action by elite jonin from all villages.
Presently, the Army of Shadows is attempted to fan out and secure their control over the lands of fire and water through a combination of armed patrols, checkpoints and fortified strongpoints to limmited success. Stay behind cells of allied shinobi have already begun conducting raids and hit and run attacks on these more isolated units to good effect and forces of the surviving villages are beginning to mass on their borders with the land of fire in anticipation of further attacks. The more difficult terrain of these mountainous and desertous regions is likely to significantly hamper the less mobile foot soldiers of the Army of Shadows.
In all, the next stage of the war seems likely to be a much more drawn out affair, without the explosive pace of the early invasion. HAving been surprised twice already however, the allied villages are on guard for more surprises from their enemy and are feverishly gathering intelligence to determine the ultimate goals of the Army fo Shadows and how they plan to go about achieving them...