With so many Major Expedition spells there's no real reason for another one and especially not in a form of ground-placed effect. And yes, Nightblades miss ground-placed AoE class damage skill.Path of darkness was and never was meant to be AOE but a mobility/escape it still fulfills it's limited role quite well.
I can AoE very nicely with Steel Tornado.. i think its time half these idiot NB's drop the 2h sword and get some dual daggers