Abilities having differentiating properties is meaningless if the other opponent has access to an ability like time stop, where it just cancels out any form of fighting back that Black has.
Assuming it is fast enough to catch him before he stops time again, and assuming that it's in character for him to just go for the kill right off the bat.
@SnifProAwaken Lancer of Black tends to only use it in the concept manip matter when it'd catch his opponent off guard, normally he'll shoot it off from the ground instead of from directly inside them
Star Platinum is pretty damn precise and will most likely sense the vibrations before the arrival of the initial attack appears before his observation.
So he'd likely avoid the initial attacks, pull out a time stop, and pummel Vlad for a bit, if Vlad lives through that he realizes he's in a tough spot and puts a stake through Jotaro's heart