Wicked Vengeance is probably the #1 2-piece DPS set in the Game. Only available from Gear Dungeons and Crafting but has the ability to roll Exclusive Gear which is what makes it so strong.

Exclusive Gear has no rules. So you can get an ATK%, Crit. Rate, Crit. DMG, ATK Spd. piece which normally isn't possible on the left side.