Invasion of Tanakreg
Tanakreg was attacked by the Word Bearers Legion led by a Dark Apostle by the name of Jarulek. The local PDF, numbering approximately 200,000 men, was subsequently slaughtered. Minimal casualties were suffered by the Word Bearers due to propagating cult uprisings and internal corruption of people inside of the higher echelons. This caused the Air-Defense turrets to be turned offline due to sabotage of the power cores during the assault, leaving the skies open for Deep Striking Chaos Marines. The Imperial deployment saw one Imperator Titan used: The Exemplis of the ancient Legio Ignatum of Mars. Another Mechanicus machine was used, an Ordinatus Machine, an enormous tank-like vehicle with a powerful Sonic Weaponry Cannon used by Titans attached to it. This sonic cannon blasted ultra-high and ultra-low frequencies which shattered armor, flesh, and stone alike under the sonic barrage.
Tanakreg saw the construction of a Gehemehnet, an immense Chaos entity built from the remains of the capital city and bodies of the dead. It was presumed that this massive tower was to transform the planet into a Daemon World, but instead was used to shatter the planet's crust and reveal the Monolith beneath. The Word Bearers believed that the Necron tomb was a weapon that could be used against the Imperium of Man in order to disable warp travel in a given area, this artifact which causes this horrifying effect is called the Nexus Arrangement. The Word Bearers unknowingly unleashed the Necrons, and it can be reasoned that this was one of the first encounters with the Necrons themselves. The Necron Lord of the planet of Tanakreg was called The Undying One, a Necron Lord mounted on a hybrid of a Destroyer body and the tiny immaculate scarabs that make up the Lord. Upon entrance to the tomb Marduk and the Dark Apostle found a "sea of silver" which was revealed to be these insignificant scarabs, the smallest being no bigger than a grain of sand, together they formed the Necron Lord. This also reveals a different way of regeneration not seen in any other Necrons recorded.
Among the Imperial forces sent to reclaim the planet, the Elysian Drop Troops and Adeptus Mechanicus pursued different agendas. The Imperial Guard wished merely to annihilate the Chaos Space Marines and retake the world, whilst the Adeptus Mechanicus desired to keep the Word Bearers from discovering the Necrons.