Catching up a bit with all the thread comments so far, in detail...
In a world of fabulousness, vampires, pillar men, and Stone Masks.
Personally, I'd probably word it under "In a World of Fabulousness and Cursed Bloodlines". Because if you've heard the opening of the first JoJo, then it's melodramatic 'blood ties' or something.
And besides, that way, you get options of say, 'Comic Book Arcs' of what the GM is, in case you want the famous JoJo's or go outright Dio.
No.
If you want JoJo, it's Phantom Blood only.
Well then, all aboard a potential 'Noble JoJo' vs 'Dastardly Dio' shippers all aboard. To either pray Dio get's burned by Dragon Lies, or becomes savvy enough to turn her into a Dragon WMD. OR to try and hook in Jonathan's Heart... Even if we have to outright burninate Elena's heart/soul/body for being a Dragon Waifu Yandere's 'rival'. Or burninate DIO if he becomes too much of a Vampiric threat to our Anchin, or a whole slew of other things.
Best case scenario, we could get like, a Half Draconic Joseph here! Think of him being that 'Crazy Awesome' Rippling Berserker, with an inherited case of Chunnibyou? But that's far,
far ahead of our game.
Now to eagerly wait for Revolver Ocelot to become her Anchin and witness the magnificence in motion
... If we go full Ocelot, and he sincerely bluffs his way with double-think to outright tsun/lie her to Dragon mode when convinient, to the point of the mental breakdown that this version of 'Archin' loves her 'dragon' self, it'd likely become a quick route to full on Dragon mode/transformation.
Which reminds me, if by some chance we're able to pick say, the MG3ish era timeline, could~ we also have it be akin to WWII/3rd Holy Grail War if chosen? Because it'd be one thing to be a Servant of The Boss/Naked Snake/Ocelot, and another thing imagining helping those 'Stealth Ops' guys form their own Mercenary Base while contending with Moonlit Conspiracies on top.
(Now imagining Big Boss killing Lords at a memetic stretch, like a Boss/Magus Killer.)