Quote Originally Posted by RSP View Post

Has nothing to do with being “rules lawyer”. DM dispels (or attempts to dispels) everything on its target. You can house rule it to be “pick just one spell” but RAW, what you’re targeting matters.

That’s why the question is important: if the DM targets the SB, SB is gone, but no other spells on the character are affected. Whereas if the character is targeted, the object SB may be unaffected.
The point is if someone wants to dispel the Shadow Blade, telling you specifically that is what he wants, you don't deny it just because the person says he casts Dispel Magic on the creature holding the Shadow Blade to be rules lawyerly picky on the difference between whether he casts it on the creature or the Shadow Blade itself.