SBR

[waxen saddle]

How does gyro's steel balls hit D4C as it is a stand

[dusky plaza]

@waxen saddle, your Spin Rank is now 1!

[serene coyote]

good question, its because stands have a compact state that can interact with objects and a ghostly state that can pass through objects
for example, when silver chariot was fighting ebony devil (the doll stand), he had to enter his compact state that allowed him to cut up ebony, but left him vulenerable to physical attacks like the blade ebony attacked him with

stands of course also have a ghostly state that allows them to pass through objects and walls, like when whitesnake phased through the bars in the heavy weather arc
if stands didn't have a compact state that could interact with the outside world, they wouldn't be able to touch or punch people

imagine if when jotaro shot himself with the pistol in the jail cell, star platinum's fingers went through the bullet due to not being able to grab it and he just died

this is also why star platinum can punch people instead of just passing through them like a ghost

gyro's steel ball hit d4c while it was in a compact state