Just as the question topic says, is he evil? In other games, like the Elder Scrolls, there are superbeings like Anu and Padomay, which represent stasis and change, they have no moral compass. Likewise, there are the Aedra, which are 'of our ancestors' and the Daedra, which were not of the people of Nirn's ancestors, again, there's no good or evil associated with them.
Some of the Daedric Princes are far more malevolent, but even then, their true will is unknowable. There was the Aedra: Umaril the Unfeathered, which was an Aedric being, of the same gods that the people of Nirn worship, but was an Auroran, and essentially a tyrant king.
Sithis is the "Dread Father", but is akin to an abyss, although those in the assassin's cult: the Dark Brotherhood worship him and kill people in his name, it's not said that Sithis is evil.
So is Zodiark evil? Or, are the Ascians simply doing their own thing?
For that matter, is Hydalyn "good"?