i was a little shocked to discover black mages literally can't win even with a gross advantage against melee types. It basically went something like Eq- 10 seconds... so that's like 4 attacks at what? 250? 500 on a good day? yay. 1000-2000 damage (double for maxed gear and criticals) against dude with 5000-10,0000 hp. Now he's at 3000-7000 and then chain interrupts your every action during the 180,000 year cooldown for eq. and sure cast... Of course, if the opponent has stoneskin, you might be lucky to see the bar flicker.
Right now black mages are dominating slaughter, but dying badly in secure. Yin Yang.