Which mage class is worth to invest empress set on?

You're welcome. I'd admit I'm also curious about this topic as I love mages (I have all of the mages sans Luminous and Flame Wizard as the former isn't out yet) and I do want at least one other character than my Phantom as a sub-main. On the other hand, given that it's already ridiculously expensive to fund over here I think I'll either be making my Evan or Luminous as a sub-main and perhaps BaM as a sub-sub main since my Evan and BaM both have critical rings.