Hades was originally planned to be the final boss as evidenced by early concept art of the Hill of Despair showing your party facing Hades in the area instead of Necron, but Hades was instead changed to be an optional boss. There are eyes on the face of his sword and on his throne. Blinking disembodied eyes are also seen in the final battle arena, showing the connection between Hades and the original final battle. Incidentally, eyes are also a feature of many Terran structures (e.g. Pandemonium), perhaps implying a deeper connection that was lost or severed in the final cut of the game.

While no exact reason for the change was given, it is believed that Hades ultimately did not fit the theme as an end boss. Hades is based on Greek mythology as a God of death who would have wanted to bring death to everyone. Necron on the other hand is an original entity based on the Greek word for "death" that wanted to bring an end to existence itself.