ΔE 15.7, loose: different enough that you should pick on purpose. Warpfiend Grey is more muted, warmer than Wolf Grey.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Warpfiend Grey is more muted, warmer than Wolf Grey.
The same difference applies the other way round: Wolf Grey is more saturated, cooler.
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 Wolf Grey on the colour wheel See Warpfiend Grey on the colour wheel
All matches: Wolf Grey equivalents · Warpfiend Grey equivalents