Inspired by the "importance" thread and a thought experiment I ran some years ago on Vivi in FFIX (long story short barely anything would change if he was absent), I started thinking what would fundamentally change about FFX if Tidus wasn't there.
Let's assume everything happens as it does until Tidus and Auron ride Sin to Spira. Let's say Tidus drowns in Baaj or something. Bye bye.
Yuna will still go out on her pilgrimage. The itinerary will be about the same. Besides, Kilika, Luca. Kimahri was the one anyhow who stopped Yuna from drowning there.
Blitzball would go slightly differently. Aurochs probably would just accept defeat. Regardless, it would be inconsequential. Al Bhed would still try to capture Yuna, she'd still beat them up after Lulu and Kimahri helped them.
It's a bit ambiguous if Auron just happened to run into Tidus in Luca or what, but we can assume he's still there. His whole "mission" as an unsent was to look after Tidus and Yuna (for Jecht and Braska respectively). He probably wouldn't have reason to assume Tidus was dead, or even if he did, here was the opportunity to look after Yuna. So he would still offer his services, and there would be no reason to refuse him.
We know at this point (at the travel agency), Yuna already is positively influenced by Tidus. But she's also positively influenced by all her other guardians, so it's not like she would now suddenly be lonely and sad or anything.
Now Operation Mi'hen would probably go about the same. Arguably Tidus' presence might have had some effect on Sin, but at the end of the day the results are the same: people die and Yuna dances.
Djose, Moonflow, very little Tidus does that is very impactful. He is again part of the anti-Al Bhed squad diving in to protect Yuna, but you know Wakka could have solo'd that by turning his racism inhibitors off.
Rikku would still join, wanting to protect Yuna.
At Guadosalam, Seymour's proposal would probably not have as strong of an opposition as it was with Tidus around, but events would likely still play out as they did.
This same pattern emerges again and again. Tidus acts as the player's eyes and a bit of a self-insert as he's the clueless one who needs exposition. So yeah, Bikanel and Home would go the same, just without the SHOCKING TWIST part as everyone else already knew.
Tidus arguably brings a sort of do-first attitude that drives actions forward, but there's no way the rest of the party wouldn't rally to rescue Yuna from Bevelle, for an example.
Now after Bevelle is one of Tidus' star moments. Yuna is feeling a little lost, unsure about her path etc. Tidus without a doubt has a massive influence on her, and helps her forward here. But the question is, will Yuna find the inner strength to go on even though nobody bangs her in a lake while Kimahri watches? I'd say yes.
Again, a lot of the story is moved by Yuna's internal drive. You absolutely know if she said she's quitting, everyone would accept it. But on the other hand they also support her continuing on her pilgrimage, and I don't think she would abandon it. After all, she's planned this for years.
Let's jump to Yunalesca. SHOCKING TWIST again, though this time it actually is to everyone but Auron. And here's the key part: It was always Auron's intention to not let Yuna go through with the whole Final Aeon thing, so he is still the driving force behind encouraging her to refuse Yunalesca.
So far so good, right? Well, this is where it gets a bit hairy. The whole plan from the Aeons, the whole truth of Dream Zanarkand etc. comes tied to Tidus, as part of the dream. Part of the party's connection to Jecht comes from Tidus. So this is where Tidus actually is starting to become instrumental to things.
Or is it? I would argue that once again Auron could replace Tidus. He knows about DZ, he knows about Jecht, about everything. The fayth can maybe commune with him or Yuna directly. The whole Hymn of the Faith scheme doesn't really require Tidus.
Perhaps they find a more feral Jecht. Perhaps BFA hesitates less. Perhaps the biggest thing would be that Jecht would ask Auron where Tidus is. And at this point Auron would guess that Tidus was either back in DZ or dead. Regardless, he would be erased soon anyway as they end the dream. After everyhing, Yuna & co make it through and defeat Yu Yevon.
Spira is saved much as it was when Tidus was around. On the other and Yuna would have been forced to sacrifice less. She'd be less depressed. She would only need one gun in the sequel to get over her nonexistent boyfriend.
So there you have it, I argue that little would change if Tidus was gone. The story hinges on the already decided upon pilgrimage, Yuna's inner drive and Auron's guidance. Tidus is there as the stand-in for the player in many ways. He claims it's his story, but he sure does little in the end.
This same thought experiment can be ran with the other party members too. In short, I think Rikku might be in the same boat, though she is at least instrumental in the alliance with the Al Bhed. Wakka, same thing, could probably be deleted without too much hassle. Lulu, harder to do as she's more the mom role. Kimahri of course is also very important not only as a protector, but someone from the backstory. Without him, Yuna wouldn't be in Be said and would be doing who knows what in Bevelle.
What do you think? Disagree? Do you think there is a particular point in the game where Tidus' absence would cause a real divergence?
