Quote Originally Posted by boilerph
Ok but you are still combining Kakashi and Kisame's statement into one. The point I was making is there is no way that Kakashi is going to infer permanent eye damage from "It's dangerous to use your eyes too much." That same warning has been given many times to many different characters and it was always in regards to chakra usage. There is no precedent set for Kakashi hearing that and thinking eye damage. In general, we interpret what we hear based on past experiences and thus Kakashi would just interpret that as a warning about the chakra strain of the technique.

That fact that Kakashi uses the word "besides" is implying that on top of the chakra requirements Kakashi had made an extra insight into the dangers of the technique. I still think finding the scroll is the most plausible solution.
They're Akatsuki members, why would Kisame give a warning as something so trivial as Chakra usage to an experienced Sharingan user. Mangekyou Sharingan is not always used, and Kisame just said it's dangerous. If Kisame was worried about chakra usage as a problem, he'd have told Itachi to not have Sharingan on constantly. Cause if you look throughout the series, there's hardly a time when Itachi doesn't have them on. Again, like in an earlier post of mine, people are disregarding Itachi's next statement of "Kakashi-san, you couldn't have..." and his shocked reaction to Kakashi's statement of how bad has his eye sight gotten.