I love Pokémon and have been watching the anime/cartoon ever since I was a little child! Pokémon is still popular!
In the Galar region, Ash hasn't caught any starter Pokémon. Both the fire and water starters went to Goh much to the disappointment of many Pokémon fans. Grookey is such a cute Pokémon and Ash should catch this grass type to boost his chances of getting to the top in Galar region. Grookey evolves into the fearsome Rillaboom, a powerful gorilla looking grass type.
7. Shiny Grimmsnarl
This is another cool looking Pokémon from the Galar region. The regular colored one is a good dark and fairy type Pokémon. But the shiny one looks really awesome with white fur. For some reason, Grimmsnarl reminds me of Gollum in Lord of the Rings. Anyways, if Grimmsnarl joins Ash's team, Ash can have the edge when fighting with psychic, ghost, and dragon type Pokémon. Don't forget the gigantamax Grimmsnarl, it looks like one of the transformers.
Hoopa was introduced in the Movie, Pokémon the Movie: Hoopa and the Clash of Ages. This ghost and psychic Pokémon is so mischievous; it calls out all sorts of Pokémon from his rings. Upon releasing his full power, Hoopa transforms into its unbounded form which looks like a giant genie. How awesome is that? Also, Hoopa had a strong connection with Ash Ketchum. It is really sad that Ash didn't add Hoopa to his team. That would make the animation show even more entertaining to watch because Hoopa likes to pull pranks!
5. Goh's Cinderace
Do you feel that Goh's Cinderace should go with Ash? Cinderace loves to show off its cool fire moves and hates to lose. But Goh concentrates on catching other Pokémon all the time. It must be really boring to be with Goh. Also, it makes me mad that Goh actually didn't really want to catch Scorbunny at first. He only wants to catch Mew at the time. How pathetic! It would teach Goh a lesson if Cinderace leaves Goh and joins Ash's team instead.
This recurring mythical Pokémon had a strong connection with Ash. But, in the end, it didn't end up on Ash's team. This is really unfortunate because it was very clear in the beginning that Meloetta really wants to be at Ash's side. Normally a very shy and invisible mythical Pokémon, it voluntarily followed Ash and became very interested in Ash's journey. Even though Meloetta is compact in size, it's fire power is still formidable.
Out of all the legendary and mythical Pokémon that Ash met throughout the series and movies, Victini made the strongest connection with Ash. It is almost surprising that Victini didn't end up joining Ash's team. The writers just had to say that Victini wants to travel the world instead of going with Ash. But with the natural flow of things, it was very clear that Victini is super fond of Ash and the two had a strong connection. With Ash Ketchum's talent training fire types, Victini will surely shine on Ash's team.
Do we all remember that Ash caught a Larvitar? It was attached to Ash but ultimately ended back with his mom. It's really too bad that Ash didn't get to raise Larvitar. Now that the series has aired many episodes since the release of Larvitar, it is really time for Ash to become the trainer of a Tyranitar. Also, to achieve the top of Galar, Ash Ketchum really needs more powerful pseudo legendary Pokémon like Tyranitar. Do you all remember in the movie, The Power of Us, Ash was able to calm down a Tyranitar on rampage. So, it's really time for Ash to obtain his own Tyranitar.
This mythical Pokémon belongs to Ash instead of Goh. Seriously, the Pokémon writers need to remember who is the main character in Pokémon. Goh wanted to catch Mew from an early age which is not typical; boys usually like big and powerful Pokémon instead. It would be really satisfying to see Mew pick Ash over Goh. Then, through Team Rocket's Meowth, Mew tells everyone the reason why he doesn't like Goh. That episode of Pokémon would have tons of happy fans everywhere.