|Real Name:||king of Ephyra, Sisyphus|
|Originally From:||Ephyra, Greece|
King Aeolus (Father)
|First appearance:||Like a Rolling Stone|
Sisyphus is a prisoner of The Underworld who was too clever for his own good, having cheated death twice - once by chaining up Thanatos so that no beings could die and again by successfully convincing Hades that he needed to return to the world of the living to obtain a proper funeral.
Burdened with the eternal, difficult, and repetitive task of rolling a large stone up a steep hill, only for the stone to roll down as soon as he reaches the hill's peak, he is freed by Cronus, but only as long as Sisyphus can elude Thanatos. Cronus provides him with metamorphesis provided that the person that Sisyphus chooses to take his place will be one of the Chosen Ones.
However, Sisyphus is unable to kill Theresa after he captures her, revealing that while he is a schemer, he is not a killer. He escapes while the heroes are temporarily unable to die, a result of convincing Thanatos to allow himself to be chained up until Theresa is rescued, but is soon pursued by the God of death afterwards, who will stop at nothing to return Sisyphus to his place in the Underworld.
His name is the origin for the word "Sisyphean" which denotes a task which is undertaken with great effort but ultimately is pointless.