Kanzenshuu

Hm... then maybe. I think what someone said earlier about Superman initially getting along until he discovered Son's attitude towards dangerous opponents. I wonder who he'd try to fight first... or how the Justice League would react to all his different transformations. It would be funny to see him ...

The obvious choice would be Zeno-sama. Not only are you the most powerful being in Dragon World (barring Toriyama Akira himself), and could literally survive the destruction of the multiverse, but meeting all your favorite Dragon Ball characters is as easy as summoning them.

I don't think any members of the Justice League speak Japanese so... I think any chance of communication is slim.