Reason: Home page, Pixiv profile, and blog all give name as 威未図(イミズ). "fumei" doesn't seem to come from that kanji so I'm guessing it's some sort of former name of the artist.
Done. Would have preferred a normal edit but 78 images for an artist is to much to not leave an alias trail. I aliased to imizu_(nitro_unknown) however, just to avoid using an overly simple name.