The Raging Tsunamis
Millions of active regiments were sent into battle against the hordes of dark Eldar that purged this world so many millenia ago. The raging battle was conclusive that they had a will of iron, and we could not beat these barbarians without a miracle. That came in the form of a hundred deathstrike missiles! The relief from the Adeptus Mechanicus had arrived! the dark Eldar were everywhere on the battlefield, so the canoneers had no choice but to fire upon their own to wipe out the scourge of the galaxy. Few guard survived, but the remnants of the regiments joined together to build the most fearsome fighting force ever created in the guard. They salvage their weapons from the battles they win, and as of now they have the heads of over one thousand army commanders, including Warbosses, Generals, Chaos lords, Wych's, Ethreals and traitors to the Emperor on their poles at the top of their fortress, stationed on a unknown planet. It is written that they can outsmart a space marine in close combat, and that their secrecy is because of a mystical being that improves their accuracy and bravery. It is a fool who attempts to kill them, for it is certain they suffer ultimate defeat. Forward to battle! Forward to victory!
Common chants among soldiers: You're so old, you sat next to the Emperor at primary school!
I also have a Librarium Online account : IronhandMatt