ΔE 16.0, loose: different enough that you should pick on purpose. Von Evile Purple is much more saturated than Corvus Black.
Can I use Von Evile Purple instead of Corvus Black?
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Von Evile Purple is much more saturated than Corvus Black.
Can I use Corvus Black instead of Von Evile Purple?
The same difference applies the other way round: Corvus Black is much more muted.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.