Mangekyou Sharingan

[XanBcoo]

Originally posted by: Gen
Im still pretty sure it goes something like

1st user - long dead member of the Uchiha clan. Made the scrolls with the info on how he obtained.
2nd user - Itachi (whos already greatly gifted) finds the hidden scroll, kills his homey, gets Mangekyou Sharingan. A short time afterwards and with his family finding out or on the verge of finding out goes mad and kills everyone but Sasuake.

I'm going with this theory until we learn how Kakashi obtained his Mangekyou. Though I do want to add that Itachi didn't go "mad". He killed off the clan to test his own limits, and I'm certain it had nothing to do with them finding out that he had Mangekyou.

[Jadugar]

I totally agree with Xan. The above theory is a solid one or maybe thats what Kishimoto wants us to believe. We need to know the secret behind Kakashi new MS before we can get to a final conclusion. As for now Kakashi's character is taking a break and attention has been diverted to the newly arrived characters, Sai etc. We wont see him or his MS in action soon.