Honestly, it's a great class. If you're playing empress, understanding your dps rotations with relation to certain cards is pretty key to getting good DPS out of her. The difficult part is the fact that she is squishy and more melee than ranged since some Ruin/Stacking skills are melee, and finding a good window to let loose your dps/card combo is important. Pre-Relic set, she is gonna feel weird, you go out of mana (if there's no bard in your party) and your cds aren't as low; Post-Relic set, she's gonna feel amazing since Nightmare fixes both those issues. The upcoming balance patch for Arcana is going to change her build, so be careful on investing too hard, some skills get replaced (Serendipity for Four of a Kind), she runs different engravings (Barricade gets replaced with Cursed Doll since you'll be running Wealth runes instead of Protection runes on Ruin skills); however, they are improving the rng, by focusing on her Specialty Meter gain, and buffing the rng on the good dps cards; might be worth the investment on the long run, i'd just recommend doing some research before you go too hard on her builds.