who died in kakashis case?
When looking at kakashi, it seems as there doesnt need to be someone close to you dying.
Its probably more like there needs to be a certain feeling inside of the sharingan user to awaken the mangekyou.
From the way Madara told his story to Sasuke, it is pretty unclear to from where they have their knowledge about the mangekyou sharingan.
He was forced to kill his brother to awaken the mangekyou, but how did they know about it in the first place?
And to your theory, Sasuke awakened his sharingan as he wanted to protect Naruto while fighting Haku. But then his brother died and he awakened mangekyou
