We'll have to agree to disagree about Aang then ^^;

The battles would be pretty cool though, I think some tag teaming would also need to hapen like Sakura and Korra using water against Kurama, or Mako and Bolin against Kuwabara. Toguro against Naruto would also be something so see. Of course I'm sure after the fights, they could all get healed up and have one big massive potluck or something cause they're still all besties~