This card is the opposite of "Mefist the Infernal General" in a number of ways. This monster is a LIGHTFairy and Mefist is a DARK Fiend. While both monsters have the Pierce effect, when they inflict damage, this card allows you to draw 1 card while "Mefist" forces your opponent to discard. However, "Mefist" does not have a upgraded version of itself while this card has.
This card is named after the mythological character Perseus, but the name was mistranslated (Pa-Shi-Ah-Su).