
Sundakan |

Use this as a starting point and just reflavor a few things.
These abilities have literally nothing to do with what the Pillar Men can do though, except they turned to stone once.
Leaving super duper Cars out of it for a second, Wham and AC/DC (and the insignificant one) exhibited the following abilities:
Enhanced strength/speed/etc.
Eternal life
Ability to absorb chunks of the human body with a mere touch
Can cram themselves into incredibly small spaces
Can meld with flesh without harming it
Triggering a rocking theme tune
Regeneration X/Sunlight Energy
And with weaknesses to sunlight and things that mimic sunlight (like Hamon), though much much less so than a vampire.
Most of these abilities would have to be entirely unique if you wanted to keep them truer to their JJBA counterparts and that's not a bad thing.
I'd peg them at roughly CR 8 at a base level (difficult, but not impossible for a highly trained human with super powers to kill), maybe edging up to CR 10 depending on how superhuman you think Joseph really is. So you'd just need to do some balancing on all the abilities based on that benchmark.
Pillar Men like Cars would be a bit stronger and have some more unique abilities. I'd say make each "Advanced Pillar Man" have a different unique property.
Ultimate Lifeform Cars would be another matter entirely.

HyperMissingno |

I imagine positive energy would be a suitable replacement for Hamon. It heals humans and hurts vampires in universe. If that's not enough I imagine a cleric with the sun domain could do it though that's a bit specific if you ask me.
They also might have some sort of level drain mechanic as they can turn normal humans into vampires and regularly eat vampires.
Also they have ranks in perform (pose) and can make checks with that skill as a free action.