I just re-read the last couple of chapters and I notice the ending is pretty subtle but good.
Basically the final scene shows that once Kishida made up his mind and let go of Hayakawa, his powers peaked and it became a given that he manages to save the world.
I guess Hayakawa was saying that...
Wow. So this is how it originally ended? Thanks for providing this. I knew this series since I was a kid and only now I knew how the end of Hades turned out.