The mirror image for me was the easiest ascention quest. I play a monk/warrior by the way. I put on healing breeze as my only heal, frenzy, balthazars aura, symbol of wrath, bonetti's defense , and reversal of fortune. The stupid mirrror starts off with frenzy, which you counter with balthazar's aura. Then you start symbol of wrath and spam away with reversal of fortune. Every chance you get unload a bonetti's defense. Wash, rinse, repeat. When your health goes down to around a hundred, cast healing breeze. This build works so well because the mirror casts frenzy, and apparently doesn't know how to use symbol of wrath or balthazar's aura. I beat him first try, then went back and did the bonus, beating him in 50 seconds. Piece of cake.