I got assigned this for round 3 of the IGMC. First, congrats on getting to round 3!
First I should start this off by saying I've never played Pokeman in my life. Pokeman was a thing when I was a teen so I passed by on it and have never played the games. I post that as I feel like you were going for a monster collecting feel here, but as someone who did not play the games I feel some things need to be better explained.
For instance, the entire system feels too random. You can spend $$$ to buy monsters, get 3 then go to a battle system against others. I managed to win rounds 1 and 2, then got to round 3 where they had monsters that were so fast they went like 4x to my once and one shotted me. As it is, it felt really oddly balanced to go suddenly from hey I'm managing to getting mopped with no chance in one battle.
I feel you should have an option to slowly introduce the mechanics to the player. I think I may have done better if I had played Pokeman games and such, and kinda feel like this was designed assuming the player has played those games before. Be careful with that as you should never assume that of the audience.
Small little detail too: The tournament is not round robin, its single elimination. Round robin you play everyone once, so round 3 can't be the final round out of 7 players. Just a side note as I teach math so it stood out to me.
Overall it is a neat idea, but needs to add more to introduce new players to these kind of games. And maybe more gradual balancing so that it doesn't go from round 2 I win to round 3 not a chance.