ΔE 19.3, loose: different enough that you should pick on purpose. Wagram Blue is noticeably darker, warmer than Stormfiend.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Wagram Blue is noticeably darker, warmer than Stormfiend.
The same difference applies the other way round: Stormfiend is noticeably lighter, 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 Stormfiend on the colour wheel See Wagram Blue on the colour wheel
All matches: Stormfiend equivalents · Wagram Blue equivalents