>>10342
Daedra don't have free will. Not even the Daedric Princes have free will.
Every Daedra represents something. More powerful entities, such as Mehrunes Dagon and the other Princes, represent broader concepts: in this case, change, revolution, destruction, and so forth.
His servants are a bit simpler. To quote Imago Storm:
Faydra's clan represents the vital, but impulsive and undisciplined element of the destructive principle. Xivilai's clan represents the ambitious, but occasionally overreaching and imprudent side of Destruction. I, and my Vassal Lords, and the Dremora clan, represent the principle of Destruction as Evolution, aspiring to arts and powers of ever-increasing potency and aesthetic refinement. The Seducers are Masterless Daedra, cast adrift by the failed fortunes of their Lords, and recently accepted, much against my counsel, into Lord Dagon's service. Is that clear?
Hence, when Mehrunes Dagon, as Daedric Prince of destruction, gave free reign to the other two and accepted in a group with no master, Imago Storm gave the Apprentice the tools he needed to pull Dagon back. Not out of any aspirations to power, but simply because he believed he knew better than his Prince.
But not out of free-will: Out of compulsion, by his very nature. Not so much a matter of a servant betraying a lord, but rather, a person with multiple personalities all in harmony. Only now, they are in agreement to jump off a cliff, and one - Imago - doesn't like that. So he calls the suicide hotline, and gets the rest dragged off. Only seeing as they are not one body, things become more complicated - after all, he couldn't fix things in this scenario.
tl;dr fuck Daedra