Lady Satan and her fiancé were victims of a German bombing while on a ship. It sunk, and her fiancé died, so Lady Satan took an oath to be the foe of the Nazis.
Donning a mask (sometimes red, sometimes black) and a red evening gown, Lady Satan traveled unnoticed through the streets of Nazi occupied France as she fought the invaders using a chlorine gun.
She later dropped the bleach gun when she somehow became a sorceress who could do anything. (no story was ever shown with this taking place)
she also wore a ring in the shape of a serpent which could release gasses derived from “dragon scales” that allowed her to “unveil the shadow world."
No word on whether or not one of those gasses was chlorine.
After the war she fought occult baddies.