I've finally beaten them.I also got lucky and they just decided not to attack for a few rounds letting my heal and put up a shield.
Is there a phase 3? If I can get lucky enough to do that while avoiding my super high-damage skills because of the damage reflection, I think I can pull off phase 2, but if there's a third, I don't know if I can swing that.
Yes, wont say more then that as not to provide spoilers.