I read what happened with Rin.
If Kakashi is a copy ninja, how is he able to get the Mangekyou Sharingan without the Uchiha bloodline?
I read what happened with Rin.
If Kakashi is a copy ninja, how is he able to get the Mangekyou Sharingan without the Uchiha bloodline?
Short answer.
Sharingan wielders don't really have to be part of the Uchiha clan to activate the Mangekyou Sharingan.
It is initially awakened by the trauma suffered from witnessing the death of someone close to the user.
So you just have to have a Sharingan and witness the death of someone close to you.
Sources:
Obito in a way, gave them to Kakashi as a temporary gift. It was like Obito's will live on in Kakashi for that moment. If you recall he said something to Rin like, "there's one more thing i must do" or something like that. However, Kakashi can no longer use both Sharingans, i'm not even sure he can use one Sharingan anymore. It is still pretty confusing.
If you have already read about Rin, you would know that she sacrificed herself for the sake of Konoha. Also, she was close to Obito and Kakashi. The death of her (at the hands of Kakashi) made Obito to writhe in pain. This is also the case with Kakashi. It hence, is that as a result of Rin's death, the Mangekyou Sharingan was awakened in Kakashi. But, the usage of Mangekyou Sharingan by a non-Uchiha demands additional amount of chakra to be spent than by a corresponding Uchiha.
From the wiki,
When they (Obito and Guruguru) arrived they found Rin and Kakashi surrounded by Kiri-nin and Kakashi plunging his Chidori through Rin's heart.[14] Rin's death caused each of their Sharingan to mature into Mangekyō Sharingan, a process that also caused Kakashi to pass out.
So theoretically, as long as the user experiences an incredibly intense emotion (such as the loss of a loved one), that emotion will awaken their Mangekyo Sharingan.
Additionally,
Sharingan that originate from the same Uchiha are still linked to some extent even when wielded by separate users, at times enabling those users to see the same things.
From the Sharingan wiki page. References manga chapters 604 and 651. So Obito's seperate Sharingan were still linked as well.
Ref: http://naruto.wikia.com/wiki/Obito_Uchiha , http://naruto.wikia.com/wiki/Sharingan