So, this is a very quich theory, probably incorrect, but we've so far fought the ice titan and the rock titan, right? Well Hades still has 3 other titans up his sleeve. According to the movie, there were five titans, and we've only fought 2. So what if we fight the remainding ones in Olympus Coliseum? I don't know, I threw this together last second. Tell me what you think.

Wouldn't surprise me if we did, but I am rather doubtful it will happen.

Seems like a waste,I rather they be incorporated into the actual story of that world.

I'm sure that they'd love to do that, and that would be awesome. Seeing as how Rock Titan might still be a boss though, I'm kind of hoping that all five of them will be fightable.

It's quite possible that the other Titans could be fightable. Maybe they'll be part of Arena matches or something when you can come back to Olympus Colluseum/MT Olympus?

I really hope we get to fight against the other Titans too, because that'd provide for quite the epic battle!  Let's hope it happens!

A tournament that contains only battle with titans would be a cool idea(1 stage for each titan)

I, too, want the Lava and Wind Titans to be fightable.

I always wanted to fight the Lava and Tornado Titans! It would be super awesome if they did incorporate them