Sorry to rain on your parade, but it's not possible to get past round
four five. At least as far as I'm aware of. It's actually a huge bummer
sad Round
four five just... never ends
emo
source
Edit: err wait. In the corner, it says rounds
completed, so I guess that means we were currently on round 5 in that screenshot, not on round 4. It's been a while. Either way, you can't get to the round after that one. I'd love to be proven wrong, but I don't think anything has changed with the coliseum since I took that screenshot.