Once Ceres has become a dragon god, he gains the special power of "Absolute Luck". That means that everything he wishes for (even unconsciously) will happen whithout any effort, making him the most boring character ever.
Zecht is by far the most interesting character of this story. He disbands the Hero's party, letting the girls going back to MC. He gives up the title of Hero and works as a solo adventurer. He takes jobs that nobody else can do (like dragon hunting) and jobs that no one wants to do (like cleaning the sewers). He spends his days off in the slumbs, giving foods and healing homeless people. The Church doesn't want to help them because they have no money.
Like he says in this chapter, as the Hero, he should marry the princess. The princess despises the arrogant person that Zecht was, but falls in love with him after he changed. She gives up on her title as a princess to marry him.
Zecht becomes a Hero again because the people give him this title back, he even tries to refuse it. He becomes friend with the Demon Lord, ending the war between humans and demon for good.
And when he comes back to his village to see MC, the girls and the moms, his mom treat him like scum because he "abandonned the girls" (when the girls themselves wanted to go back to MC...)