Coming back to what made cloti canon, to me while playing the OG, was a combination of Cloud telling Tifa that only what she thought mattered, followed by the Lifestream scene. These two scenes solidified what Cloud felt about Tifa to me. The first, I was like, "woah, what are you saying Cloud, that you favoured Tifa over Aerith all this time because only what she thinks is important?" No matter how you turned that, it just meant that Tifa was just that important to Cloud, much more than anyone else. And I wasn't even aware that it was not the real Cloud yet.
Then the Lifestream scene happened, and I was just like "woah, wait, he's got it so hard for her, whaaaaaaaaaat" hahaha. If you want to say "that's in the past", it doesn't explain how he calls out for Tifa and only for her. To Cloud, all of this is fresh in his heart. He's been in love with Tifa all along, trying to impress her, attacking Sephiroth in a fit of rage and despair over losing his mother, Tifa and his village... all of this happened just yesterday for him. It doesn't make sense to say "it's in the past" because it's still very much the burning present to him, still amongst the reasons why he goes after Sephiroth. There's a reason why "Reunion" is a cloti theme, why it's engraved in the Promise and in Tifa's theme, because they both long for their reunion - and the Lifestream scene IS their reunion. And it's just sooooooo intimate, it's like Cloud's memories and heart are being inspected haha "oh yeah Tifa, whom I always loved, whom I connect all my important moments to, oh yeah, errr, I was meant to hide this y'a know" well too bad for you Cloud, your feelings are quite bare there lol.
In the OG, it's a huge turn because Tifa doesn't look so much like she has Cloud's favour prior to this. The game pushes clerith hard, to make players care about Aerith and give them the false sense of security that a love interest usually has (eg: doesn't die). You are pushed to chose Aerith over Tifa, generally speaking, and Aerith herself doesn't hesitate to flirt openly with Cloud. I remember that I became very protective of Tifa because of the way the OG treated her in the first part of the game
I didn't like how Cloud treated her, so I didn't ship cloti. It took the Lifestream scene to make me go "ok you care enough about her, I can ship you two together" lol - I suddenly feel like Marle, ehhhhhhh.
I have already said it, but I'm glad the Remake is laying down things differently. Because, as much as a shock that came out, for many people, the game pushed clerith too hard, so they thought the game had an open ending. And yeah don't remind me about cloti living together and raising two kids together yet only being friends, let's get real there, this was a stupid argument. But back then it wasn't established that the HA Highwind scene was the canon route, and many people disproved it with Cloud's last vague line "I want to meet her". Yeah, let's say that I hope that Remake will not have this line again or the LTD will never end.
At least now we have a pretty solid foundation for cloti that can only expand in the next game. I am looking forward the Kalm's flashback - and everyone's reaction there, hopefully we will have an aerti convo about it too. I'm also looking the Gongaga flashback, because I'm quite sure Aerith will be mandatory this time around to have around. Then there's Costa del Sol (bikinis, pretty please SE?) and Gold Saucer for a little fun~~