Here are some videos I made a while back showing some of Siegfried's whiffing issues:
Video 1: Shows some of Siegfried's whiffs.
Video 2: Shows some more of Siegfried's whiffs.
Video 3: Shows some more of Siegfried's whiffs, as well as a bad one of Astaroth's and a few of Voldo's.
I would make some videos for other characters too, but I mainly play Siegfried so I don't have many whiffs with other characters recorded unfortunately.