The Valorous Crusade
In the grim darkness of the 41st Millennium, there is nought but war.
Prologue
The galaxy is at war, there is nowhere during this time where peace is seen. Mankind is on the brink of collapse constantly, only through the actions of its many forces does it hold on. The Astra Milltarum or Imperial Guard, millions of men and woman conscripted to fight and die if need be for the Imperium of Man. The Adeptus Mechanicus, the Machine cult, beings who've shed their mortal skin in favor of the cold way of steel and wire and maintain both a fighting force on their massive forge worlds and act as the engineering branch for mankind. The Adepta Sorortias, the Sisters of Battle, woman sworn to fight in the name of the God-Emperor of Mankind and its church. The Inquisition, the secret origination that protect mankind, at what ever the cost. But the greatest of these are the Adeptus Astartes, the Space Marines, these men are the embodiment of the Emperor's might, blessed with bodies and minds capable of more than any normal human could endure, gifted with a special gene-seed, a piece of a Primarch, a son of the Emperor and they know no fear.
Against them are the various alien species found in the galaxy, the savage Orks, whose massive bodies, ability to naturally adapt to any environment and unique reproductive cycle make them a wide spread threat.
The Aldaeri or Eldar, a once proud and very psychical powerful people who are now dying as a result of their actions, once the dominate species in the galaxy, their fall came about suddenly and without mercy via She Who Thirsts due to their constant indulgences into the most hedonistic acts. Since then the race has been split into various factions, the Craftworlds wish to save their race by postponing their enviable demise at the hands of the god their race spawned via strict pathways to walk throughout their very long lives, the Drukhari or Dark Eldar continue with their hedonistic ways of old and hid out in their hidden city of Commorragh striking out the galaxy through raiding and pirating. The Harlequins are a group dedicated to the Laughing God, Cegorach and put on performance of the fall of the Eldar race but also are a fighting force themselves. The corsair fleets act like the Drukhari but to a lesser extant and the Exodites are Eldar that have chosen to live a much more rural live than the rest of their species.
The Necrons, once a live species these beings became living machines long ago to defeat an enemy, at the order of their gods, the C'Tan whom their rebelled against and shattered into fragments, Entombing them in their monoliths as well as themselves for eons. They are now awakening more and more now and wish for nothing but that all life was extinguished.
The Tyranids are a hive mind species that consume whole worlds of their bio-mass, leaving the planet bare and lifeless. The arrive in numerous hordes of bio-forms and collect and destroy anything that gets in their way. They also have a form of scouting force in the form of Genestealer Cults, Tyranids that over time gain the appearance of humans thus making it easy for them to overthrow planets of their government.
Lastly are the T'au and their fledgling empire, the T'au are a species broken up into casts, each one providing towards the 'Greater Good' which is the Tau philosophy that each being has a role to play in the collective to make the whole better. The fire caste are the warriors and soldiers and use advanced mech battle-suits to engage in battle. The water caste the politicians and are the one that bring other species into the Greater Good such as the Kroot and Vespids. The earth caste are the engineers of the Empire, they are the one that build and maintain the battle-suits of the fire caste as well as the other technologies of the Empire, the air caste of the pilots of the empire and are the ones that aid the fire caste ground forces via fighter wings and bombers attacks. The last caste are the Ethereals, they are the ruling caste and as such are the one that dictate all the orders to everyone else.
But it is not with these alien species that mankind has its greatest enemies but rather from within in the form of Chaos, the malicious, diabolic daemons from the Warp, the immaterial realm parallel to our own. It is in this realm that beings are able to use psychic powers and where our emotions rule not logic. Here the gods of Chaos twist the minds and bodies of mortal to serve their whims. Khorne the Blood God demands nothing more than blood to spill, Nurgle the Plague Father wishes to spread his blights and death across the galaxy, Tzeentch the Great Changer wants discord and total chaos for everything via plots and schemes and Slaanesh or She Who Thirst, the Lord of excess what the galaxy to quiver in pleasure and pain. 10,000 years ago the greatest of the Emperor's sons, Horus Lupacal of the Lunar Wolves and eight of his brothers with their legions joined Chaos and rebelled against their father and started the Horus Heresy, a seven year long ,and greatest, civil war the galaxy had ever seen which ended with the deaths of the Loyal Primarch Sanguinus of the Blood Angels and Horus himself upon his flagship, The Vengeful Spirt, and the ultimate entombment of the Emperor of Mankind upon the golden throne of Terra, since then he has staid there, guiding mankind through psychic messages.
But now there is a new player coming into the game, a collection of species like the Tau but are not governed by a philosophical idea but by a religion that speaks of a Great Journey and their name is …. The Covenant.