Board Thread:Theories and Speculation/@comment-33005792-20170901151707/@comment-33005792-20170904140754

Vladosaurus wrote: Actually, i think it's very likely that the Kara members received their marks (if all of them have it) from Otsutsuki members. Boruto pretty much killed Momoshiki, hence why the later was able to give Boruto his mark as probably a spirit. Kaguya was not killed, she was sealed away. That would make sense of course if Momoshiki was actually killed. For me at least it's clear that Kara are linked one way or another to the Otsutsukis. It would be odd considering the fact that apparently so many humans fought or met Otsutsukis. I personally think that the Kara members are either Otsutsukis themselves, or another entity perhaps? I find it hard to believe that they are actually humans. I definitely think Kara are human. Boruto is human and has received a mark. The Otsutsuki themselves have never been shown with a mark like this anywhere as part of their own design.

You're right about one thing though which I got wrong in the original post, I forgot that Kaguya was sealed away, not killed, which does explain why Naruto and Sasuke didn't receive a mark. But it furthers the probabilty that the way to receive one is by killing an Otsutsuki which I can't see so many ninja accomplishing without it being known of by the rest of the shinobi world by now.