"Be careful who you surround yourself with" is the kind of grating advice that's meant to save teenagers from messy relationships. But when the teenager in question happens to be the heir to the Iron Throne and future ruler of seven conflict-prone kingdoms, suddenly that advice holds a lot more weight. In "House of the Dragon," Princess Rhaenyra (Milly Alcock and Emma D'Arcy) is surrounded by power-hungry sycophants, ambitious social climbers, a homicidal uncle, a backstabbing BFF who...