ΔE 15.1, loose: different enough that you should pick on purpose. Mortarion Grime is a little lighter, cooler than Voodoo Shade.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Mortarion Grime is a little lighter, cooler than Voodoo Shade.
The same difference applies the other way round: Voodoo Shade is a little darker, warmer.
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 Voodoo Shade on the colour wheel See Mortarion Grime on the colour wheel
All matches: Voodoo Shade equivalents · Mortarion Grime equivalents