Syll'Esske, the Vengeful Allegiance, is two beings ruling as one: Syll'Esske the daemon and Esske the mortal, bound together in a single monstrous form by an act of rebellion that pleased the Dark Prince beyond measure. The mortal Esske was a slave who murdered his masters; the daemon Syll'Esske was a herald who scorned the tyranny of greater daemons. When the two met, they recognised a shared hatred of every yoke and throne, and Slaanesh rewarded their union by fusing them into a towering, twin-souled champion.
Together they rule a vast host of daemons and mortals as equals, an unheard-of allegiance in the fractious ranks of Chaos. In battle Syll'Esske wields a great axe and a sceptre of command, the daemon-half striking with monstrous strength while the mortal-half directs their followers with brilliant, spiteful cunning. Their shared purpose is the tearing-down of hierarchies: they hunt the proud and the highborn, and take exquisite pleasure in humbling those who imagined themselves above others. To follow Syll'Esske is to serve the one lord in Slaanesh's service who promises not indulgence but revenge — and delivers it, gloriously, upon anyone who ever presumed to rule.