ΔE 11.8, fair: the same colour family, but not a straight swap. Magnus the Red is more saturated, cooler than Banshee Brown.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Magnus the Red is more saturated, cooler than Banshee Brown.
The same difference applies the other way round: Banshee Brown is more muted, 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 Banshee Brown on the colour wheel See Magnus the Red on the colour wheel
All matches: Banshee Brown equivalents · Magnus the Red equivalents