Knights of Cygnus Skill Tables

Isaac, what does lightinig charge REALLY do except for giving ' lightining boost to the player ' ?
because im a striker and im confused about the skill build. You see, every skill in 2nd job is pretty much important, and I have to leave 1 skill at 11 or 14 [forgot MaxHP, Knuckle Mastery, Knuckle Booster [ Wind Booster ], Energy Charge corkscrew blow and Blast, and this new skill ' lightining charge '.
So, should I leave lightning charge and max the other skills instead?
or leave blast /corckscrew and max lightning charge instead?