How did Dianmu become the goddess of lightning?
After Lei Gong wrongfully killed Dianmu, the Jade Emperor revived her and made her a goddess, and Lei Gong’s wife.
How does Dianmu’s lightning help her husband dispense justice?
Dianmu’s lightning illuminates her husband’s targets, so that he can look closely and make sure they’re truly guilty before striking.
In Chinese mythology, Dianmu (電母)—or Leizi as she is commonly known—is the goddess of lightning and the wife of the thunder god, Léi Gōng (雷公). Her alternative appellation is Léigōng zhī qī (雷公之妻), or “Lei Gong’s wife,” which often gets shortened down to “Leizi” in English transliterations. She flashes giant, polished mirrors to create the phenomenon of lightning while her husband uses a drum to generate the sound of rolling thunder.
Leizi and Lei Gong worked with three assistants, Yúnzhōngzǐ (雲中子), a youth who had the power to generate clouds, Fēngbó (風伯) who was the god of wind, and Yǔ Shī (雨師), who made it rain upon the Earth by dipping his sword into water and allowing the water to drip from the blade.
A series of tropical storms have been named after the goddess including the 2004 typhoon (also known as Typhoon Helen in the Philippines) that struck Japan.