I haven't seem a single guide using the ninja powerset. The ninja MMs I see in game seem to only have traps and trick arrow secondary powersets. Ninjas seem to be melee powerhouses, so I'm suprised I don't see more people combining the ninja offense with a defensive secondary like dark miasma. A ninja overlord with shadow powers doesn't seem very farfetched for roleplaying either. Is there some sort of fatal flaw in ninja/dark miasma that I'm not seeing, and why isn't this combination more popular?