If I attack with Naganadel GX's "Stinger GX" attack, how would it work if my opponent has received a "Double Prize Loss" or a "Quad Prize Loss" penalty earlier in the game?

For a "Double Prize Loss" you only need to take one more prize from the remaining three to win the game. If your opponent received a "Quad Prize Loss" you win the game because you have less than four prizes remaining.

Relevant cards

SMA_SV63