Zeus's sister was Hera. This is extremely messed up because they were married, and had kids, but that is how it goes
Zues, the king of the gods in Greek mythology, was a complex figure who displayed both positive and negative qualities. He was often associated with justice, leadership, and protection, but he also had a reputation for being vengeful and unpredictable. Ultimately, his actions depended on the specific myth or story being told.