Jougan and the Otsusuki clan
Every dojutsu in Naruto ends with ‘gan’ which can be translated to eyes. The name Jougan is a combination of two words, Pure and eye, in simple words Jougan means Pure eye.
What does this mean? Is it the true eye form of the Otsusuki clan? Was the sharingan and rinnegan a flaw in the clan? We have no answers for these questions as of now.
In the Boruto movie, Momoshiki and Kinshiki were from Otsutsuki clan. There is a chance that there are more Otsutsuki clan members out there, as Kaguya was accompanied by beings from outer space to the earth in her arc.
Another possibility is that there are more powerful enemies with unimaginable destructive power in another dimension or galaxy.
Kaguya alone was way too much for Naruto and Sasuke together, imagine handling thousands of Kaguyas! The plot sure is getting interesting.