Answer:
to save Megg
Step-by-step explanation:
Hades took Megg's soul and brought it to the underworld, he knew that Hercules would come and try to save Megg. Hades thought that Hercules would not make it trying to save her, so he made a deal with him. (to be honest, I don't remember the deal). To Hades surprise, Hercules made it alive. After saving Megg, his next task was to save Olympus and defeat Hades.