Bweh?
Aedra and Daedra ALL existed at the same time. But the lines that seperate them only appeared in the creastion of Nirn. Those who made it were the Aedra. Those who didn't were the Daedra.
And those three are "good" by the fact they're the anticipations of the Tribunal. they're not actually "Good"....
Mephala's sphere is obscured but most definately tied to murder
Boethiath is treachry, deceit, and overthrow of authority
Azura...well, Azura is Dawn and Dusk, but what I've seen and read of her, makes me think she's little more than an Attention mother of mine.

And well, Daedra are the kinda things that are intrinsically "bad", IMO. they're not human, they're driven by different motivations than mortals, and well...selfish. Any pact made with Daedric Prince doubtlesslyt serves the prince's goals better than yours...you just don't realize it..yet.
The only Aedra who were "mortal" were Arkay and Tiber septim, but that's BS, really.
Tiber Septim is none other than the sundered God, Lorkhan. Yeah. He's alive. One does not kill a god easily.
And Arkay, well, the mortal thing wa sonly proposed in one book (a fairytale kind of one no less) so I don't give much credit to it.

/end lore lesson-rant.