Lord of Heaven, father of gods, Zeus treats all the Heroes as if they are his rambunctious, rebellious children.
After being caught unnumbered times in the midst of trysts with countless mortal women, his divine wife finally gave him an ultimatum:
'If you love mortals so much, go and become one. If you can prove yourself faithful, then return to me as my immortal husband. Otherwise, go and die among your creatures.'
Zeus found her logic (and her magic) irrefutable, and agreed to her plan. He has been on his best behavior ever since, being somewhat fonder of immortality than he is of mortals.
But to prove himself worthy of his eternal spouse, he must continue to pursue victory on the field of battle.
