[@Lewascan2] It's not even canon to JJBA that nothing except Stands can affect or detect stands; both Cheap Trick (a stand) and Kira (a stand user) were killed by the ghosts of Reimi's alley.

I only mean "special club" as the idea of a superpower that is completely undetectable and uncounterable by the rest of the cast, because only characters from the same property (of which we have none so far) would be able to meaningfully interact with it.

Stands also aren't genetic, they're the ripple of the soul, an expression of spiritual energy into a battle-avatar. The Joestar family all has stands because The World is a fucked up stand, not because they're genetic stand users.