Naruto Shippuuden Episode 27

[February]

How does killing a friend magically grant you a new ability? If there's any logic behind that requirement, then it would be to first feel like shit because you killed a friend just to get more power, and consequently, if you survive that miserable feeling, you would become desensitized:

Yeah, I dont understand the logic behind it either, people have been saying that the guilt creates some sort of mental trauma which affects your bloodline ability?
Even so, if you killed your family member, wouldnt it serve the same effect? Since I would be just as horrified to kill my parents as it is to kill my best friend and same weight in guilt.
This requirement is unreasonably unrealistic

[Hiroshi01]

kakashi did learn the mangekyo sharigan but it's his own version and remember they call him the "copy ninja"

[ASSpirine]

kakashi did learn the mangekyo sharigan but it's his own version and remember they call him the "copy ninja"

He can copy jutsus, the Mangekyou Sharingan is not a jutsu. It's an eyeborn power you could say. You can't just obtain sharingan by copying it, but by stealing the secret. And that happens with dissecting the body or some sorts. (The Hyuga story )