Hades was in love with Persephone, the daughter of Demeter. However, Demeter did not approve of Hades. When Hades became frustrated with Demeter's interference, he "kidnapped" Persephone and brought her to the Underworld. Demeter was furious. She caused a winter storm which killed many crops and people in the land of the living. She asked for Hercules' help to go to the Underworld and retrieve Persephone. Hercules discovered that Persephone had not been taken against her will. She was in love with Hades. Hercules negotiated a deal wherein Persephone would spend half the year with Hades and the other half with Demeter (HTLJ "The Other Side").
Hades seems to one of the respectable members of the Olympian Pantheon, until he attempts to murder Xena's daughter Eve, who is prophesied to bring about the Twilight of the Gods. Before this Hades would help Xena in some sticky situations, even calling her "old friend" before he attacked her, saying it was for the greater good. Xena eventually kills Hades with her fire-breathing technique after being imbued with the power to kill Deities. It is unknown if anyone else took the throne of the Underworld but it's likely his sister did.
Hades is one of the most powerful Greek gods. He can teleport, throw fire balls,throw green energy blasts, kill a mortal, wipe out memories, create windows to oversee people in the underworld,has super strength,can go back through time as mentioned in the epsisode (armagedon0 that all gods have this ability and he has the power of healing as mentioned by aphrodite in the episode (motherhood) that all has this ability but can only heal with athena's blessings, become invisibile, reanimate and resurrect mortals. He posseses the Helmt Of Hades that can turn someone invisible, even to gods,when gods are in the underworld they lose their powers as mentioned when ares told xena that in hades's kingdom he has no powers (god fearing child) and in the episode (the other side) demeter told hercules that he will has commands of demons, ghosts and monsters.
