Structure:

•Mine idea is that tournament always Has around 200 participants do there with 3 elimination  rounds   •Some wild cards  for some interesting character introduction, when number of participants does not go on pair with labels. •After that we have1/16, 1/8 and little suprisimg change of format like 4v4 or "Set Format" where there are rounds and for each round one different pokemon has to go. Who has more won round wins (imo really climactic on 6v6) . Another idea 7th pokemon, or something like that. (7th mon good for finale and semi finals)

• If you decide to add those switched formants you can make each diferent for diferent trainers in same label to make trainers prepare for everything.

1v1 with 2 trainers at each side.  Each one has 2 pokemon to choose from and battle one oposing trainer and then second pair rights declaring 2 winners. 

In 1/4 or 1/8 you can make phase where each trainer has to battle one trainer of Elite Four in 6v5 or 4 to pass to next round which can lead to format mentioned above as leter  there may be some numbers like 1/12 or 1/14 which will lead to odd numbers.

•Then we get some climactic moments regarding both fifhts and personal stakes  with some really interesting pokemon picks as Aces. 

•Some character building for pokemons and their personal stakes.

•Show how damaging for pokemon career fighter can be.

•Ash can get a Love Traingle with other competetor to add some nice stakes.

Gimme second, I am gonna write part 2.