By the sound of things he tried to make a lot of trouble in his world especially for a man named Hercules. [Effectively, anyway. They never really did get super into the details of motivation or goal.] He released a number of monsters to wreak havoc and was responsible for kidnapping and manipulating others as well. He's been stopped before but I doubt that he's given up. It's hard to permanently stop a god from doing what he wants to. [What with that whole 'immortality' issue.] And like you said before time is a bit complicated here. [As in it's more or less meaningless in relation to their home worlds, anyway.]

Yes Hel is the goddess of the dead here. We don't usually see very much of her. She's not the most talkative of the gods. Her district can be a bit rough though. Some of the people in her House aren't the kindest. [Understatement of the year.] That area is also where the amusement park is but it's not always the best place to visit.