The sharingan cannot see as much as the byakugan. If anything, neji would find out its "blind spots" and have lee attack them. Neji could use rotation to counter amaterasu.susanoo's "blind spots"? didn't know byakugan could see those thought it was just chakra flow, and besides that, sauske would see everything with his sharigan, he may not be able to keep up with 8 gates lee but all he has to do is kill Neji with some amasuta fire how ever you spell it and defend himself from lee until it wears off then lee is ****ed