ΔE 24.8, loose: different enough that you should pick on purpose. Magenta Blood is much more saturated, cooler than Sekigahara.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 25). Magenta Blood is much more saturated, cooler than Sekigahara.
The same difference applies the other way round: Sekigahara is much 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 Sekigahara on the colour wheel See Magenta Blood on the colour wheel
All matches: Sekigahara equivalents · Magenta Blood equivalents