Mephiston Red vs Hellspawn Red

How close are they?

ΔE 15.4, loose: different enough that you should pick on purpose. Hellspawn Red is noticeably lighter, more saturated than Mephiston Red.

Can I use Hellspawn Red instead of Mephiston Red?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Hellspawn Red is noticeably lighter, more saturated than Mephiston Red.

Can I use Mephiston Red instead of Hellspawn Red?

The same difference applies the other way round: Mephiston Red is noticeably darker, 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.