Information on the cameo
Hades (Ancient Greek: Ἅιδης/ᾍδης) is the Greek god of the Underworld and the dead. He is the oldest male child of Cronus and Rhea considering the order of birth from the mother, yet is disputed as the youngest, considering the order regurgitation by his father. He is one of "the Big Three" gods, consisting of himself and his brothers, Zeus and Poseidon. Hades is the only one of the three to not have a place on Mount Olympus, as he lives in the Underworld, welcoming the recently deceased and choosing their fate based on how they lived their lives.
Appearance in the rap battle
Hades appeared during Thor's first verse, during the line, "Who would ever worship someone as abusive as Zeus is? You're ruthless to humans; your crew is like the clash of the douches!", slaughtering the Greeks alongside Zeus, Athena, and Ares. He also appeared in Zeus' second verse along with other Greek gods such as Athena, Ares, Poseidon, Dionysus, and Aphrodite.