I'll just casually mention Dark Pit is clearly holding his dark pit staff in the leaked portrait picture, not pit's usual blades/bow.
Not to give credit to a text leak, but the dark pit part isn't too far fetched.
(That being said, considering pit's got idle poses holding his bow or dual swords, he's clearly already designed to work well with exchangable weapons. Dark Pit could easily be a Pit clone with weirder attack properties + more visual flair in the shape of more varied weapons, e.g. palms, claws, staff, blade etc. it'd be fairly easy to swap the weapons in tons of Pit's move to make sense with various kid icarus weapons while still making dark pit technically a clone animation/skeleton-wise..)