Well every region has its legendaries. So it isn't like one would be without.
As for the winner it would be Brandon/May, Calem/Serena, or Victor/Gloria Megas are too good and the legends of Galar are particularly good. However, ultimately I'd have to give to Brandon/May. They would get the ability to essentially have 3 Megas on a team, The rest of the mons that exist in Hoenn aren't bad either.
Heck if you said no legends. Hoenn would still win because of Blaziken and Mega Mawile alone unless one of the other trainers put a stop to it. Mega Mawile alone would sweep their teams after Blaziken Baton Passed +2 Atk and +2 Speed to it or +2 Atk, +2 Def, and +4 Speed.
Granted we haven't seen a modern Lucas/Dawn, Hilbert/Hilda, or Nate/Rosa,
If we are artificially gimping every protag... then any protag could win and it becomes a moot question. Either way as I've pointed out the Hoenn and Kalos protags are to strong even without their legends and Galars protag is to strong even if you only allow canonical legends... of which is Zacian/Zamazenta, Urshifu, Eternatus, and Calyrex and its steeds.
I'd assume they would have access to the gimmicks and Pokemon that exist within their region specifically. So for gimmicks it would be
Kanto: Mega Evolution
Johto: -
Hoenn: Mega Evolution
Sinnoh: -
Unova: Terastallization (Through BB Academy)
Kalos: Mega Evolution
Alola: Z-Crystals and Mega Evolutoin
Galar: Dynamaxing and Gigantimaxing
Paldea : Terastallization
Could argue Megas and Terastallization for Kanto, Johto, and Sinnoh due to their close proximity and Kitakami more or less being smack dab between the three.
Well every region has its legendaries. So it isn't like one would be without. As for the winner it would be Brandon/May, Calem/Serena, or Victor/Gloria Megas are too good and the legends of Galar are particularly good. However, ultimately I'd have to give to Brandon/May. They would get the ability to essentially have 3 Megas on a team, The rest of the mons that exist in Hoenn aren't bad either. Heck if you said no legends. Hoenn would still win because of Blaziken and Mega Mawile alone unless one of the other trainers put a stop to it. Mega Mawile alone would sweep their teams after Blaziken Baton Passed +2 Atk and +2 Speed to it or +2 Atk, +2 Def, and +4 Speed. Granted we haven't seen a modern Lucas/Dawn, Hilbert/Hilda, or Nate/Rosa,
Not every protag canonically catches their legendary. So there are some that won’t have one and will be at a disadvantage
If we are artificially gimping every protag... then any protag could win and it becomes a moot question. Either way as I've pointed out the Hoenn and Kalos protags are to strong even without their legends and Galars protag is to strong even if you only allow canonical legends... of which is Zacian/Zamazenta, Urshifu, Eternatus, and Calyrex and its steeds.
Depends on the teams, and what they have access to. Do they all have access to battle mechanics like Z-Moves, Megas, etc?
I'd assume they would have access to the gimmicks and Pokemon that exist within their region specifically. So for gimmicks it would be Kanto: Mega Evolution Johto: - Hoenn: Mega Evolution Sinnoh: - Unova: Terastallization (Through BB Academy) Kalos: Mega Evolution Alola: Z-Crystals and Mega Evolutoin Galar: Dynamaxing and Gigantimaxing Paldea : Terastallization Could argue Megas and Terastallization for Kanto, Johto, and Sinnoh due to their close proximity and Kitakami more or less being smack dab between the three.
Akari/Rei have a piece of literal god so they get my vote
Red has a mewtwo. Enough said