Abaddon the Despoiler, Abaddon the Warmaster of the Black Legion, Abaddon, another personal chosen of the Chaos Gods, Abaddon, Horus's most loyal and powerful son, was caught in a fit of impotent rage.
After his disgraceful defeat on Vigilus, he had suffered a truly crushing defeat on Taliban.
When Guilliman advanced on him with the Emperor's Sword and Jonson with the Emperor's Shield, Abaddon had known how the battle would end.
Unsurprisingly, the other Daemon Primarchs had mocked his miserable defeat, and the Chaos Gods had berated him endlessly for it. Not only had they blamed him for the defeat, they had also held him responsible for the disappearance of the Daemon Primarchs Lorgar and Perturabo. The Four Gods had declared that Abaddon must undertake a "Penitent Crusade" to appease them after this affront.
At Tzeentch's command, the Daemon Primarch Magnus had completed a legendary spell, teleporting Abaddon and a small squad of his trusted followers to a mysterious location, all while mercilessly mocking his incompetence.
"You don't deserve to call yourself Horus's successor, Ezekyle. Only when your life becomes as expendable as your Black Crusades will you deserve the title of Chaos Warmaster."
That had pushed Abaddon's fury to its breaking point.
"Stop changing the subject! To burn the False Emperor to ashes and annihilate the galaxy, we of the Black Legion will endure anything! But I just don't understand. We're all trying to make the galaxy burn, so why is it always the one who does the most who gets treated the worst?!"
The Warmaster of the Black Legion raged, "Magnus, what's wrong? You dare do it but won't admit it? You dare lecture me about the Sons of Horus? You think you're worthy of discussing them with me, daemon?!"
"Hmph." Magnus snorted and stopped arguing with Abaddon.