Helaena, Daenerys, Euron, Quaithe - Glass Candle Theories - Song of Ice & Fire - House of the Dragon

Rumors that Helaena or others could be using glass candles on House of the Dragon Season 3 gave me a good reason to hit you with my best glass candle theories, plus an exploration of their powers, both known and suspected. Did the Targaryens use them on Dragonstone & how does a candle explain the Dornish Letter mystery? Is Euron using a candle to corrupt people like Leyton Hightower or Daenerys? What will Dany see with the glass candle Marwyn the Mage is surely bringing her? How is Starry Wisdom Cult using the candles to enact their agenda? Are glass candles keeping the ghosts of the Great Empire of the Dawn alive somehow??? A brand new Winds of Winter predictions theory here too!