"Don't worry, Miss Joy, we've got it all under control." Ash patted his chest, indicating that everything was grasped well.
There are many reasons for challenging Sabrina: the advice from some experienced folks in the group, his own curiosity, and the desire to battle an Elite Level using his Pokemon.
Moreover, the tougher the challenge the Gym offers, the more motivated he becomes.
If there weren't even a sliver of hope for victory, Ash wouldn't foolishly go forward with the challenge. As some experienced folks in the group said, such one-sided battles only serve to damage self-esteem and confidence, with no real benefit.
But now with an Elite Level Gastly, he could at least have a go at Sabrina.
Additionally, the king of the harem in the group, Ash, mentioned that Sabrina was essentially a little girl with a psychic scar. Battling her early and saving her from this mental shackle would be ideal, otherwise...
Sabrina might very well get pulled into Team Rocket!
In many parallel worlds, quite a few Sabrinas ended up joining Team Rocket because Team Rocket exploited her psychic vulnerability, dragging her into the abyss.
Sabrina joining Team Rocket has posed considerable obstacles to Ashes in various parallel worlds, even causing many wicked deeds.
As the saying goes, one thought leads to good, another to evil; the balance between good and evil hinges on who can first influence Sabrina. This is why, upon seeing Ash encounter the millennial Gastly, some experienced folks in the group recommended that Ash challenge the Saffron Gym.
Yet, every world follows a different trajectory; in some worlds, even if Ash didn't challenge the Saffron Gym and never met Sabrina, she still wouldn't join Team Rocket, possibly even returning to normal...
It just goes to show that parallel worlds represent an array of possibilities. The nature of Sabrina in newbie Ash's timeline remains uncertain. The group's insights are indefinite; it relies on Ash truly meeting Sabrina.
"Speaking of which..." Ash silently stared at the Pokemon Center's ceiling, slowly speaking, "Have you seen enough?"
Misty & Brock: !!!
"A-Ash, what are you talking about? Seen what?" Misty's voice trembled slightly as she edged closer to Ash. Following Ash's gaze, she saw nothing.
Could it be that something akin to the spirit in Maiden Gorge was present here?
"Ever since we entered Saffron City, there's been a strange force surrounding us. It should be superpower-related, meaning we've been monitored since entering Saffron City," Ash said, astonishing everyone.
Upon entering Saffron City, he sensed a gaze that focused all attention on him, making it hard not to notice.
The other party likely detected his presence and knew he was an unusual person, hence the consistent focus on him, even after reaching the Pokemon Center.
Yet, once he uttered 'Have you seen enough?' that prying sensation vanished. The other party probably figured he'd visit the Saffron Gym shortly, making it pointless to snoop here instead of waiting to meet him.
"Feels like it's someone quite frightening!"
"Didn't Miss Joy mention earlier that she's quite scary?"
"...Is she still listening now? Hopefully, she didn't hear what I just said?" Misty suddenly recalled that Sabrina had been spying on them earlier, causing her to lower her voice.
"Rest assured, she's gone. I'll first contact Professor Oak." Ash waved to indicate Sabrina was no longer around, then used the Pokemon Center's phone to dial Oak's Research Institute.
When the call connected, Professor Oak was still eating instant noodles. For some reason, whenever Ash called him, he was usually eating instant noodles, despite it being neither nutritious nor healthy, mostly because it saved time.
Professor Oak was truly relentless for the sake of his research.
"Hello, Professor Oak."
"Oh, Ash! Is this call because... you've already reached Saffron City?"
"Yeah, first send Gastly over to me. I'll send Pidgeotto back."
"Alright, I'll fetch Gastly. He's been enjoying himself in the backyard lately, occasionally teaching your Butterfree. He's quite skilled, Butterfree learned Tailwind under his guidance." As Professor Oak walked away from the phone, he commented.
As a spirit that's lived for millennia, his prowess may not be the absolute pinnacle, but in terms of skill diversity and versatility, it far surpasses ordinary Pokemon, even mastering many skills otherwise impossible for itself.
For instance, the time it transformed into Ho-Oh during a battle with Ash was thanks to the illusion skill Gastly mastered, allowing it to take on the form of other Pokemon and even use their skills, abilities, and attributes.
It's practically an advanced version of Ditto's Transform skill.
However, this power has limits; it can't wield the forces of top legendary Pokemon. For example, when it transformed into Ho-Oh, it only had Ho-Oh's appearance and some presence, unable to use Ho-Oh's exclusive flames, divine role, abilities, etc.
Still, this self-taught skill is already incredibly impressive. Thanks to this skill, Gastly can devolve post-evolution and learn many skills it couldn't ordinarily master.
That's why it's able to guide Butterfree at Oak's Research Institute to learn the Tailwind skill.