This thought just occurred to me talking to Segev in the Hex thread: since all builds are encouraged to use their "Concentration slot" on something, this is an unused design space for martials. What do you guys think? Would it be a good idea to give Martials class features that use the Concentration slot (maybe at the subclass level, so those subclasses that get spells don't get sad)? And what good features could there be that would fit the martial fantasy, the themes of each class, but could also be considered something that would require "concentrating"?