CROSSOVER MADNESS

 Here's my review of 1931's DAUGHTER OF THE DRAGON, which is a "spin-off crossover" in which Fu Manchu's daughter Ling Moy gets her own one-shot feature, and Fu himself is demoted to being part of Ling's support cast-- the opposite fate to the prose daughter's fate, since Fah Lo Suee is always subordinate to the prose "devil-doctor." Because Ling Moy has her own automatic stature by virtue of being the star, this counts as a high-stature crossover.

MONSTER MASHUPS #91

 Just stumbled across a manga called PRINCESS RESURRECTION NIGHTMARE, whose first story includes both a sexy vampire and a sexy werewolf.

ADDENDUM: I see now that this is a sequel to a slightly earlier manga series, simply PRINCESS RESURRECTION. An immortal "queen of monsters," Hime by name, gathers a small retinue of helpers: a vampire, a werewolf, and a human boy, Hiro, who becomes her servant after Hime brings Hiro back from the dead. The group ends up fighting various other monsters who challenge Hime's reign. After that series concluded, PRINCESS RESURRECTION NIGHTMARE revived the characters with a "mystery" angle, in that they come together but don't remember their shared history.