I had some time today to do some translating from the Final Fantasy X-2 Ultimania Omega, and I thought I'd present my translation of the information concerning Tidus and Shuyin, as many have wondered what exactly is up with those two (why they look and sound similar):
Quote:
[Connection with Tidus?]
The appearance and voice of Shuyin resemble Tidus, but the two are completely different in actuality. Shuyin is a man of the past; he lived 1000 years ago in Zanarkand, the metropolis city of summoners. Tidus, a pyreform, was a resident of its summoned replica, Dream Zanarkand.
Be that as it may, Dream Zanarkand was in fact created with the idea in mind that it be the ideal [representation] of Zanarkand's existance, a wish given form. Since its existance was the model for everything in Dream Zanarkand, this extends to its inhabitants also. When thinking about this with regard to Tidus, one cannot deny the possibility that this [was the case] with his personage and Shuyin. However, most inhabitants of Dream Zanarkand would marry one another and have children, continuing the cycle of life. For this reason, the genes of the dream's inhabitants began to blend in a complicated way, and with these impurities, the duplication of [Shuyin's] personage cannot be certain. Even if it is true that Shuyin was the model for Tidus, this would not mean that their connection is close.
Basically, it doesn't tell us for sure. Personally, I doubt that Dream Zanarkand would have gone 1000 years without a Shuyin being added previously (most logically at the time it was created). With this in mind, I'd guess Tidus was probably a descendant of Dream Zanarkand's Shuyin.
That's all for the moment. I'm going to be translating the rest about Shuyin later, and I'll add it in here.