I was reading through the DoT battletome, and came across this guy:

Is it me or is this the ULTIMATE daemon prince?

So I incorporated some of his backstory into mine... Essentially the fluff about him is the preamble to the Children of Xenthos.

After thousand of years of having El'an'zeth standing guard over Uzalith, t he great library-city was eventually attacked by the Thunder-Wrought, a Stormhost of Azyr. By then, almost all of Uzalith had felt the power and strength of 'The Architect', as Tzeentch is known. After a whole year of brutal guerrilla combat through the pristine streets of Uzalith, the citizens fled to a final stronghold: The Hex Citadel. It was at the gates of this iron fortress that El'an'zeth fought Emmanuel Witchbane, a Lord-Veritant of incredible might and expertise. Every spell flung by El'an'zeth was deflected by Emmanuel, and every stab and slash directed at El'an'zeth was parried with similar skill. After an hour of non-stop combat, El'an'zeth was beaten, and his body was paraded through the streets of Uzalith in celebration. The city was in turn burnt to the ground, and what few citizens survived lived in fear and terror.

Yet, from the broken body of El'an'zeth, the change-cycle continued. From the ashes of Uzalith came Xenthos, a daemon sorcerer like no other. Claiming to be a reincarnation of El'an'zeth's spirit, and known to be a prophet of his return, Xenthos brought society and prosperity back to the remains of Uzalith, teaching its people the secrets of wyrdflame and sorcery and taught them the Enlightened Path: the true way of The Architect.

Reborn in vengeance and magistry, Uzalith and her people marched to war, seeking the Thunder-Wrought, and, having found them, delivered the worst punishment of all. Death was to good for them; they would simply be reforged in Azyr. No, the punishment for the Thunder-Wrought was simple in its genius. Xenthos, casting a mighty spell, and aided by ninety-nine other wizards, turned the stormhost into the servants of one thing they had sought to destroy. The Thunder-Wrought were forever bound to protect Uzalith, and, exposed to the sheer change-magic that dwelt in the library-city, slowly warped into the first Chaos Stormhost: that of Tzeentch...

Thanks again guys, hoped you enjoyed it, and thanks for looking!