Who is Nergal (Erra) from Myths from Mesopotamia: Creation, the Flood, Gilgamesh, and Others and what is their importance?

Nergal, also known as Erakal, Erra, Ninurta, and Herakles in Greek mythology, is the chief God of the Underworld following his decent into Ereshkigal's realm. Nergal refuses to bow to Ereshkigal's vizier during a banquet, and he is subsequently punished by being sent to assist her in the Underworld. The two have a passionate affair, after which Nergal escapes, but he later returns to claim the throne.

As Erra, the god of war, he ravishes Babylon to prove he is as powerful as Ea, only to be calmed by Ishum. His release of the seven terrors into the lands, however, is responsible for destroying much of creation. As Ninurta, he is the avenger of Ellil, killing Anzu following his theft of the Tablet of Destiny.