ΔE 16.2, loose: different enough that you should pick on purpose. Mephiston Red is a little darker, more saturated, warmer than Wyvern Fury.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Mephiston Red is a little darker, more saturated, warmer than Wyvern Fury.
The same difference applies the other way round: Wyvern Fury is a little lighter, more muted, 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 Wyvern Fury on the colour wheel See Mephiston Red on the colour wheel
All matches: Wyvern Fury equivalents · Mephiston Red equivalents