Tournaments a bit too limited and restricted. I mean, there's three tournament types for restrictions, but there's only one true bracket style. There are also some battle types that could be included to the battle arena as well. Listed below are some ideas for the battle arena.
Tournament or battle style suggestion:
Well, there could be a random Pokémon battle or tournament. This would be when someone would do a RNG for three Pokémon for each trainer to use. These would be a level decided by the RNG decider, or maybe a simple 50 or 100. The trainer's existing Pokémon do not affect this battle or tournament style.
Tournament bracket style: double elimination
Well, it's simple. A double elimination tournament. If you're beaten once, you get one more chance to win again. The losing trainers move to a second bracket, while the winning ones remain in the current bracket. The final battle will be the second bracket's winner against the first bracket's winner. The first bracket's winner must lose twice, however and the second bracket's winner must only lose once.
I hope this gets looked over, and if it does, thank you for reading. Anything said here that is clearly an opinion is not to be taken as a thought of fact. It is opinion. My opinion.