ΔE 19.7, loose: different enough that you should pick on purpose. Runic Purple is a little lighter, much more muted, cooler than Coven Purple.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Runic Purple is a little lighter, much more muted, cooler than Coven Purple.
The same difference applies the other way round: Coven Purple is a little darker, much more saturated, 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 Coven Purple on the colour wheel See Runic Purple on the colour wheel
All matches: Coven Purple equivalents · Runic Purple equivalents