ΔE 17.4, loose: different enough that you should pick on purpose. Evil Sunz Scarlet is warmer than Mindcrime Magenta.
Can I use Evil Sunz Scarlet instead of Mindcrime Magenta?
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Evil Sunz Scarlet is warmer than Mindcrime Magenta.
Can I use Mindcrime Magenta instead of Evil Sunz Scarlet?
The same difference applies the other way round: Mindcrime Magenta is 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.