A theory as to why Shuyin looks like Tidus

[Squall of SeeD]

well it dose say that tidus is a dream so he has to have some basis in reality so the fayth took shuyins featues on tidus and changes the personality which means tidus is a dream of shuyin just all nicey nice and therfore there must have been some one like ject as well and the passage of time thing just means that the dream and the real world work on the same basis of time.

Again, though, 1000 years have passed. The people of Dream Zanarkand are populating the place on their own. They're living, breathing, reproducing people, and their copulation with one another brings forth new people. The Fayth have no reason to be randomly creating someone and tossing them in, and we know they weren't, as Jecht and Tidus' mother are his parents. He was born like anyone else.

Just thought of something else. Shuyins attacks are exactly the same a Tidus’ (save the name of course). How do you explain that? (other than Square is lazy).

Well, we have to keep in mind that Square is lazy. About 80% of the stuff in X-2 was reused from X, ranging from environment maps to NPCs. Generic character designs were suddenly being used for some of the central NPCs, such as Ndhala, Beclem, and Yaibal.

Something like this really isn't all that worthy of consideration with the other points to consider.