The bull shows up repeatedly in the story of Minos and Theseus. Europa is abducted by Zeus in the form of a bull. Pasiphae is forced to lust after a bull. The Marathon bull kills Minos' son, and the Minotaur in the labyrinth is part bull.
Theseus metes out justice to each of the six foes he faces on his way to Athens. Theseus makes the punishment fit the crime. Literally.
Theseus triumphs over unjust and savage beings throughout his story. He defeats the bad guys at every turn, from his "Six Labors" on the road to Athens, to the wild Marathon Bull, the unnatural Minotaur, and beyond.