Name: The Ninja Nuns
First Appearance: Quasar #32 (Mar. 1992): "The Tomb of Mar-Vell"
Number of Appearances: 1
Note: fictional characters in "Revenge of the Ninja Nuns" movie
Within the Marvel Universe, the super-hero/actor Simon Williams (a.k.a. Wonder Man) starred in a B-movie titled Revenge of the Ninja Nuns. Based purely on the title of this film, it is not entirely clear whether the "Ninja Nuns" are heroes or villains. But because films with the phrase "revenge of" in their titles are usually sequals, we are assuming that this film is a sequel featuring "the Ninja Nuns" as central characters. It is likely that they are the protagonists and heroes of the film, despite their titular desire for "revenge."
Having not yet read this story ourselves, we can't be entirely sure, but as far as we can ascertain, this film was merely mentioned in this story. The film nor the "Ninja Nuns" were actually seen. If this is the case, then story writer Mark Gruenwald would be the only "creator" of the Ninja Nuns, and their "appearance" would be a "mention" only.
Suggested links for further research about this character and the character's religious affiliation: