Well, Riderman ala Gackt-style hasn't much canon presence though he could be filled out by using the original background - even if I do include the PVs for the songs Gackt wrote for the series - but gah so much canon to have to find then.

Gackt and Hyde wrote the screen play for Moon Child basing it off of Gackt's book Moon Child, and he has a couple albums that parallel the movie. So yeah, it is a cool thing.