Here is a translation of the Brazilian Darkstalkers fan project for Street Fighter RPG. Adding supernatural creatures to the SF setting is a common thing for fans to do, since Street Fighter’s genre is effectively: Supers + Martial Artists, and many (most?) Supers settings have characters from every genre, but also:
In 1997, White Wolf licensed the World of Darkness name and logo to Capcom for use on the third arcade game in the Darkstalkers series. That game, which was originally titled Vampire Savior: The Lord of Vampire for its Japanese release, was localized for arcades in North America as “Vampire Savior: World of Darkness”.https://whitewolf.fandom.com/wiki/Capcom
As with any game/setting fusions, there are implications to consider, as well as unforeseen problems to at least expect to happen. The world of Darkstalkers is quite different to Street Fighter, so a SFRPG set there will involve major changes. An alternative that I am pondering is the world is initially the standard one in SF, and then Pyron and the Darkstalkers start to arrive. For those that have read/played Palladium’s Nightbane, setting the game at the start as the Dark Day event occurs.
Other World of Darkness adaptions can be found in Warrior’s Fist, Werewolf: the Apocalypse 3, Vampire: the Masquerade 5, Changeling: the Dreaming 6, Mage: the Ascension 8. Plus Street Fighters In The World Of Darkness S7.
Darkstalkers SFRPG. Here is a link to the folder of Street Fighter translations, which includes all the Warrior’s Fist (PdG) issues, Virtual Combat Cards, the epic Circuit Guide, Circuit Guide – Basic, both Solo systems (Meet the Strongest & Dominus), Spartacus, Tekken, Darkstalkers, and the Mortal Kombat files. The whole folder can be downloaded as a Zip file 🙂