Board Thread:Boruto Discussions/@comment-34938099-20180619182027/@comment-34938099-20180620123429

In my opinion, Momoshiki was the first person to awaken the Rinnegan. He literally existed even before Kaguya came on Earth a millennia ago. If someone says that it could be possible that Momoshiki didn't have the Rinnegan at that time. But then again, we already know that Kaguya already feared Momoshiki, Kinshiki and Urashiki ever since she came on Earth. And as far as I know, Momoshiki's Rinnegan is the only thing that makes him powerful and God-Like. His Rinnegan is the only reason why Kaguya would fear him in the first place. Otherwise, Momoshiki literally doesn't have anything OP aside from his Rinnegan. So, I'm 100% sure he had it even before the time Kaguya ran away from the Main branch of the Otsutsuki Clan.

Or it's also possible that Urashiki or the Otsutsuki Clan Leader or some OP member awakened it  even before Momoshiki.