This level has definitely reached the point where evolution is possible, but the reason for not evolving is simply because they don't want to evolve.
Some Pokemon are unwilling to evolve, perhaps because they think evolution is ugly, or perhaps to prove that they can become strong without evolving. Pikachu is a classic example of being unwilling to evolve.
He just wants to maintain his Pikachu form, and Bulbasaur might have the same idea as Pikachu.
But Pikachu can amplify his combat power with partner form, while Bulbasaur doesn't have such a form...
If he doesn't evolve, it will greatly impact his combat power in the future.
However, Ash also respects the choices of Pokemon. If Bulbasaur doesn't want to evolve, then let it be. It's not like you can't become strong or stand at the peak without evolving.
After the Three Starter, it's Kirlia. Having just evolved to Advanced Intermediate level, after seven days of settling, she's reached Advanced Level and is about to level up again.
This speed of leveling up remains unparalleled within the team.
Pikachu has just steadily leveled up to Elite Advanced Level.
Pikachu's speed of improvement isn't fast, but he has an incredibly terrifying trait that he seemingly doesn't encounter bottlenecks.
Over the past month or so, Pikachu hasn't been stuck at a level. Although the speed of leveling up isn't fast, it's stable, making progress every day.
Plus, with the fixed ability value gained from leveling up... his improvement can only be described as outrageous. Ash even wonders if Pikachu might face off against an Elite before the Quartz Conference?
Such a thing is still too distant. Right now, Pikachu can at most try his luck in a Gym, but thinking of an Elite is a bit too much.
Lastly, there's Riolu. After a week of treatment, Riolu's condition has significantly improved, with all qualifications restored to B-level. He's actually ready for some basic training now.
But to quickly recover the defects in his body, it's best not to do anything that drains his physical strength, so Riolu remains at Newbie Beginner Level. Once he fully recovers, he should undergo a leap in improvement, similar to Ralts.
Aside from Ash, Misty and Brock's Pokemon are also steadily improving. However, since their training and battles aren't as intense as Ash's, their Pokemon's improvement can't compare and isn't worth mentioning.
Additionally, Ash and the group encountered a migration of Butterfree on the road.
Ash isn't particularly interested in the Butterfree migration. Migrations usually aim for reproductive prosperity, but seeing so many Weedle and Caterpie in the Viridian Forest, it's clear Butterfree can reproduce without migrating south.
Moreover, his Butterfree is still with Professor Oak, so bringing Butterfree here for migration is out of the question.
Besides, that's a Pokemon he has painstakingly raised. It's well-fed and well-cared for in the backyard in a beautiful environment. Why migrate south to endure hardship? No need to endure hardship voluntarily!
So migrating south is not an option.
But Brock mentioned that now seems to be the season for Butterfree to mate, so Ash found a nearby Pokemon Center, transferred Butterfree back, and let Butterfree see if it found a suitable mate.
In the end, Butterfree did fancy a pink Butterfree, unique in color compared to normal Butterfree and admired by many Butterfree.
But thanks to Ash's well-raised Butterfree, the other Butterfree were no match, and with Team Rocket's assistance, Butterfree successfully won the beauty's affection.
Did they migrate south together after their union?
I said migrating south is impossible. Ash immediately captured the pink Butterfree as well, then sent them both to Oak's Research Institute to continue their love story.
The environment at Oak's Research Institute is also suitable for Butterfree to live and breed, much better than migrating south.
Ash was deeply moved, as a Caterpie that had become his Pokemon now had a home of its own. It's only been about a month!
Some Pokemon find a mate in a month, while some people, like you, Brock, remain single for twenty years...
Sparked by Butterfree, Brock's yearning for older sisters grew even stronger...
...
On the eighth day, Ash and companions finally set foot in Saffron City.
Saffron City is a major city in Kanto, arguably one of Kanto's central hubs!
Kanto's two most prosperous cities are Saffron City and Celadon City.
Celadon City boasts the largest department store in Kanto, selling a wide variety of items, making it the city with the most trade.
Saffron City also has many large malls, but more so, it houses big enterprises, among which, Kanto's largest, Silph Company, is located here. Pokeballs are one of the tools made by Silph Company.
Additionally, Saffron Gym is one of the most powerful gyms in Kanto, led by Sabrina, a Superpower User and an extremely formidable one at that!
Sabrina became a Gym Leader in the past two years, and it's said she is only sixteen and already has the strength of an Elite Trainer.
This strength has a double meaning: Sabrina has elite-level Pokemon, and... Sabrina herself is of Elite-level strength!
"...Honestly, I don't recommend challenging Sabrina, because those who fail to challenge her are said to suffer quite painfully, with many challengers developing psychological shadows."
"Saffron Gym may not be the strongest gym in Kanto, but it's definitely the most terrifying gym, bar none."
Miss Joy at the Pokemon Center advised Ash and his friends as such.
Upon arriving in Saffron City, the first thing the trio did was head to the Pokemon Center. After all, their Pokemon were quite fatigued from the journey, training, and battles, so they naturally needed some recovery.
While recovering, they also inquired about the stories here from Miss Joy and learned about Sabrina's rumors, along with Joy's warning.
No matter how strong another gym is, failing only weakens one's confidence. But Saffron Gym is different. Failing there comes with serious consequences.
This is why, in recent years, challenges to Saffron Gym have dwindled.
The League has issued some warnings, but Sabrina ignored them.
Even people from the League personally visited, and whatever happened, Saffron Gym remains unscathed, with the League ceasing to care.
The only thing noted on Saffron Gym is the word "danger," suggesting fewer challenges to Saffron Gym.
Challenging Saffron Gym doesn't pose a life threat, but it can leave a substantial psychological impact.
After understanding the details of Saffron Gym, Misty was a bit hesitant, thinking that the gym was more terrifying than she knew!
As a fellow Gym Leader, she knew little about Saffron Gym, only that it was very powerful. She didn't expect it to be so terrifying.
Brock knew a bit more but was unaware of Saffron Gym's fearsome reputation.
Only Professor Oak is fully aware of Saffron Gym, so he has always been advising Ash not to go to Saffron Gym. But Ash insisted on coming, so Professor Oak could only suggest that Ash first gather intel at the Saffron City Pokemon Center before challenging.
After all, Ash at least has an elite-level Gastly, enough to try his luck against Sabrina.
What made Professor Oak relent on advising Ash against the Saffron Gym challenge was what he learned from Gastly about how Ash captured Gastly.
He was initially puzzled as to how Ash's Pokemon could capture an Elite-level Gastly, and then the truth...
Well, it turns out this guy is a human-shaped Pokemon!!!
Guess how ancient trainers captured Pokemon without Pokeballs, without using Pokemon to tame them?
Ash is now essentially using ancient methods to capture Gastly.
Professor Oak doesn't know where Ash's superhuman strength comes from, but knowing Ash is still Ash is all that matters, and this Ash overlaps with the Ash from his impression even more.
After confirming Ash's capability of self-defense, Professor Oak gladly lets Ash challenge Saffron Gym. Even if he can't win, with Ash's power, wouldn't he be able to escape?