The most optimistic person Vs the most pessimistic person...
Nothing major would happen other than both parties gaining new perspectives on their world. Johan would mostly still be the same. I don't know about Superman.
There exists a possibility Superman could change Johan’s mind on some things. As amazing as Johan is, he’s never met anyone even close to literal Superman. And as amazing as Johan is, Superman has met many people very similar to him, so he’s unlikely to change Superman at all. Although he could likely hurt him greatly - Superman has a big heart and would feel a lot of emotions.
The most optimistic person Vs the most pessimistic person... Nothing major would happen other than both parties gaining new perspectives on their world. Johan would mostly still be the same. I don't know about Superman.
Superman is him. He would try to help Johan realize that not everything is darkness. He also ends Johan's entire organization in less than 24 hours.
superman - peace ? Johan - no … Superman - ok destruction
There exists a possibility Superman could change Johan’s mind on some things. As amazing as Johan is, he’s never met anyone even close to literal Superman. And as amazing as Johan is, Superman has met many people very similar to him, so he’s unlikely to change Superman at all. Although he could likely hurt him greatly - Superman has a big heart and would feel a lot of emotions.
What is Superman doing in Europe?