Is Tidus just a dream/dead or something?

[Shiny]

I dont agree though, if you ask me; up close shuyin and tidus look nothing alike. most likely they just had a similar build and hairstyle, and yuna stumbled upon it by happenstance. even at the beginning they were very iffy about it because the sphere was distorted and once yuna saw him closely, she instantly recognized they were different. now, for tidus being a descendant...ya I kinda see it, but there just wasnt enough...physical evidence in-game pushing the idea. they would have hinted that somehow or someway, if that was true. Most likely, it was all by chance.

I was more of emphasizing the "dreamed so hard, he was real" part. sorry if I was to blunt

It was more so his behavior that threw Yuna off that Shuyin was not Tidus. There was distortion in the sphere, true, but it's definitely evident that the two could be identical twins. Face, hair, clothing and vocals are very similar. They're voiced by the same voice actor, although Shuyin's voice is a bit more harsh because he's bitter. She wouldn't have said, "Is it you, or does it just look like you" if there wasn't a major resemblance.

The whole dream thing is relevant, but in the metaphysical sense he's more of a reincarnation. The Fayth wanted to recreate the past Zanarkand so they used people who were already dead based on their memory of what Zanarkand used to be. To allow this dream Zanarkand to be built, they mimicked the lives of people who were already dead. That's where the Tidus and Shuyin connection comes in.