Formerly a prophet, he changed himself from a man to a woman, indulging in the pleasures of both.
The blind prophet of Thebes, Tiresias was the son of the nymph Callirrhoe, and was the high priest of Apollo. He was originally born sighted, but lost the use of his eyes after being blinded by either the goddess Athena (for seeing her naked by accident) or by the queen of the gods, Hera (after he sided with Zeus against her in an argument). As compensation, he was given the gift of prophecy.
One myth referenced by the game described his encounter with a pair of mating snakes. By striking them with a stick, Tiresias was magically changed into a woman. She lived life as a wife and mother for a time before finding another pair of mating serpents. Striking again caused Tiresias to revert back to being male, and it was with this gender that he lived out the rest of his days.
Perhaps the most famous myth concerning Tiresias and his gift in prophecy was Sophocles's play, Oedipus Rex. The protagonist, a young king of Thebes named Oedipus, was charged by the gods to avenge the murder of his predecessor, King Laius. Due to the murderer never having been brought to justice, at the onset of the play, Thebes was cursed by the gods with devastating plague and famine. Oedipus turned to Tiresias for help in finding the killer, but Tiresias was reluctant to speak. This angered Oedipus, who accused the prophet of having something to do with Laius's death, to which Tiresias finally burst out that Oedipus himself, though unaware of it, was Laius's murderer. The young king ridiculed Tiresias and had him sent away. However, as he left Tiresias commented that Oedipus's parents thought him "sensible enough". These words stunned Oedipus, as he never knew his real parents, and the investigation shifts focus into finding out whose child that the young king really was. The king eventually discovered that not only Tiresias was correct in telling him that he killed Laius, but Laius was his real father. Worse, Oedipus also unknowingly married and had children by his own birthmother: Laius's widow, Queen Jocasta. Devastated, Oedipus brutally blinded himself with pins and was exiled from Thebes to lift the plague.
Tiresias made another appearance in the play Antigone, a continuation of the Oedipus myth. Prior to exile, for their disobedience Oedipus cursed his sons, Etiocles and Polynices, prophesying that they would one day kill one another. After their father was gone, Oedipus's brother-in-law Kreon became king and raised the two boys. Despite an arrangement that Etiocles and Polynices will share the throne of Thebes when they become adults, once Etiocles had the throne he refused to hand over his power, prompting Polynices to rebel and declare war on the city. As Oedipus predicted, the brothers slay one another in battle. Kreon ordered a splendid funeral for Etiocles, but decreed that Polynices and the rebels must be left outside the city to rot, on penalty of death to any who did not obey this order. Horrified, Polynices's sister Antigone buried the body secretly. Kreon had it exhumed and Antigone was caught trying to bury her brother again. Kreon decided to uphold the death penalty and had Antigone buried alive in a cave with a minor amount of food. Tiresias immediately went to Kreon and informed him that the gods were furious with his decrees, as the dead must be given proper funeral rites. He instructed Kreon to bury Polynices and release Antigone, or the gods would take away those that he loved the most and curse him for the rest of his life. Kreon immediately buried Polynices but was too late to free Antigone, who had hanged herself in the cave. Kreon's son and Antigone's fiance, Haemon, and Kreon's wife Eurydice killed themselves as a result, fulfilling the gods' curse on him.
In Homer's Odyssey, King Odysseus of Ithaca descended into the Underworld to seek the prophet's advice, using blood from a sacrificed animal to summon Tiresias's ghost. The shade informed Odysseus that Poseidon would not forgive him for blinding his son, the cyclops Polyphemus, and informed Odysseus about the suitors that are after his wife and his son Telemachus back in Ithaca. Tiresias warned Odysseus that on his journey home, he will reach the Island of Helios and he and his crew must not eat any of the cattle on the island or they would all die. The old priest told the King of Ithaca that he must journey to a land where no mortal went before (Phaeacia, a blessed land that no regular human found). When the inhabitants of the land called Odysseus' oar a "winnowing shovel", Tiresias instructed him to place it in the ground as a sacrifice to appease Poseidon. Then, and only then, would he be able to return safely to Ithaca and reclaim his throne. By this advice, Odysseus was able to successfully return to Ithaca, avenge himself on the suitors threatening his power and reunite with his family.
- In The Inferno, Dante and Virgil behold the shade of Tiresias in the fourth pit of the Malebolge, damned for his prophetic acts. Tiresias's daughter Manto, whom he bore while he was a woman and who inherited his prophetic gifts, walks with him in this circle.
- Although in mythology Tiresias died a male, the game depicts his shade as still being a woman.