Board Thread:Episode Discussions/@comment-27924662-20170419222535/@comment-734582-20170422074243

Namikazenaruto9 wrote: Boruto's Byakugan ability seems similar to Naruto's negative emotion sensing. I don't think it's either byakugan or tenseigan. Could be rare mutation.. It seems to me like a weird amalgam of an underdeveloped byakugan (no X-ray or farsight) but at the same time it's the Rinnegan equivalent (can see spirits). It also glows similar to the Tenseigan but lacks it's floral patter.

So it's probably a mutation, or a new Kekkei Genkai recreated from two clans that never mixed before, yet are known Sage descendants. (IE Rinnegan was (re-)created from 2 Sage descendant clans, despite neither having any other Rinnegan powers.) The power of kaguya split in a few interesting ways into several clans, but that's not any reason to believe those are the only possible splits. For all we know, many more powers could be lurking in clans that never surfaced because the other part of the KKG was in some other clan.

It's also possible at least some of Hagoromo's, nine Biju's or Hamura's power bled through.