Author Unknown wrote:“The first major recorded conflict of the Ebon Current was on Denruba. Reports of a relatively small infantry patrol, later discovered to under the command of Lord Vitaeus, was spotted attempting to circumvent Imperial piquet lines. Upon hearing this, a platoon of Space Marines led by Captain Seneca rushed out to repel the invaders. Unfortunately for them, their doom had been all but certified, as this was what the forces of Chaos were hoping for. Although it was never proven, historians and military investigators suspect spies and saboteurs had found an opportunity to tamper with Imperial provisions, especially their Plasma weaponry, rendering them not just useless to the wielder, but dangerous.
When the Imperials finally located the enemy, Captain Seneca immediately threw his men forward, confident that the Plasma support from behind would provide enough covering fire to soften the more powerful enemy soldiers. Of course, here is when the Devastators discovered, to their doom, that their weapons strengths were no longer true, and this ignominious underhandedness saw the valiant Astartes run to their deaths.
Seneca, appalled by the heinous presence of Nurgle affiliated Traitor Marines, arguably abandoned sound tactics and instead rushed to close the gap with them. Despite bravery unmatched, the Captain heavily wounded. He was rescued from death by his men, sensing the enemy had bested them this day.
Realising the battle was won, Lord Vitaeus himself sought out Captain Seneca, but found he had already been extracted, and instead took his displeasure out on a brave Terminator Sergeant who had volunteered to cover the captain’s escape. The Marine was killed, but his noble gesture resonates within his chapter to this day.
Captain Seneca never fully recovered from his ordeal. The noxious poisons of the enemy were said to have infected his brain as well as his muscles, affecting both his speed and reasoning. Since that day, he eschewed bodyguards in battle, instead distancing himself from his men. That being said, witnesses claimed his fury swelled to epic proportions, and many said that staying clear of Seneca during a battle rage was perhaps wise.
After the Imperial defeat, no sign of Vitaeus’s men was uncovered, despite several other scouting parties. It is assumed they melted into the surroundings, biding their time. The next time they resurfaced was during the climactic Battle for Denruba, several weeks later… “
-A History of the Fate of the Ebon Current
The Seeds Are Sown, pg 12-16
Redacted from Imperial Records