ΔE 23.6, loose: different enough that you should pick on purpose. Cardinal Purple is noticeably lighter, much more saturated than Dragon Blood.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 24). Cardinal Purple is noticeably lighter, much more saturated than Dragon Blood.
The same difference applies the other way round: Dragon Blood is noticeably darker, much more muted.
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 Dragon Blood on the colour wheel See Cardinal Purple on the colour wheel
All matches: Dragon Blood equivalents · Cardinal Purple equivalents