This movie is an unintentional gem. It wants to be a (mostly) serious martial arts/superhero movie, but because it's so incredibly bad, it's wonderfully funny instead. All the elements of great schlock are here: a bad script, bad directing, bad acting, and a low budget.
Malik Ali is a shyster lawyer who defends guilty criminals by day; by night he's The Black Ninja, a costumed crimefighter beating up bad guys in Philadelphia and getting revenge for the murder of his family. To its credit, the movie is pretty clean throughout; if it were in theaters I'd rate it PG.
This flick is right up there with Plan 9 from Outer Space and Birdemic as one of the all-time great lame movies. If you like so-bad-it's-good cinema you must see The Black Ninja.