ΔE 8.6, close: similar, with a visible difference side by side. Witchbane Plum is a little darker than Warlock Purple.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Witchbane Plum is a little darker than Warlock Purple.
The same difference applies the other way round: Warlock Purple is a little lighter.
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.
See Warlock Purple on the colour wheel See Witchbane Plum on the colour wheel
All matches: Warlock Purple equivalents · Witchbane Plum equivalents