i think i know why he looks like tidus, ok remember they told us that there was a war between zanarkand and bevelle a 100 years ago and then sin came and destroyed it. so the fayth to preserve zanarkand started to dream it up and all its people so i think that tidus was kinda like the shuyin of 1000 years ago just dreamed up by the fayth. i know theres a lot to go against this but its just a thought