Hatch is motivated to do this because Michael had destroyed his whole facility; he escaped and befriended Zeus earlier in the story and told him of Hatch's lies. When the electric children are unable to stop Michael, he feels that he can end Michael on his own. This is significant in the story because it shows Hatch's deep hatred for Michael and his whole "Electroclan" to be willing to risk his life to try and kill Michael.
Zeus enthusiastically screams that "(His) name is Zeus!" as that was what he was always known as when he worked for Hatch. He was insulted when he was called Frank after deciding to betray Hatch and him blasting the bullet out of the air and blasting hatch is proof that he is truly "Zeus". This is significant because had Zeus not done this, Michael would not be alive.
Zeus feels that using a name given to him by such an evil person as Hatch is not moral and he does not deserve the praise, but the rest of the Electroclan disagree and reassure to him that he is a "God" and a hero. This helps to welcome Zeus to the clan and make him feel loved for once, as Hatch had killed his parents.