With Sasuke losing his Rinnegan and Naruto losing Kurama, it looks like the Naruto saga is ready to rest itself on the shoulders of the next generation.
Naruto Shippuden took a huge turn when the Sage of Six Paths granted Naruto and Sasuke a portion of his own power. While Naruto received the Six Paths' Sage Mode, Sasuke unleashed the Rinnegan in his left eye.
Needless to say, it stormed the fan community when Sasuke's Rinnegan was first introduced in the Shippuden anime.
They loved the fact that it made him and Naruto the strongest shinobis at the moment.
However, in a similarly unexpected incident, Sasuke lost his Rinnegan in the Boruto manga recently, and it left fans broken-hearted.
[WARNING: Spoilers ahead]
Sasuke loses his Rinnegan in Boruto: Naruto Next Generations, explained
This tragedy hit the fan community within days of another tragedy: Naruto losing Kurama. As fans might be aware, the Boruto: Naruto Next Generations manga has already bid farewell to the beloved Nine-Tailed Beast, and it is only a matter of days before fans experience it on screen.
The few manga chapters prior to and following Baryon Mode are some of the best in the series as of now, and came with some massive surprises.
Kurama dies after using the Baryon Mode, and Isshiki Otsutsuki is apparently defeated in a sudden turn of events: He places a Karma on Kawaki at the last moment, only to find out it was a Shadow Clone.
Just as everyone was about to celebrate Isshiki's defeat, Momoshiki possesses Boruto's body, and the first thing he does is stab Sasuke's Rinnegan.
Basically, Momoshiki wanted to prevent the squad from leaving the place using Teleportation, which is one of the primary uses of Sasuke's Rinnegan. It is also at this moment that Momoshiki reveals his plans as well: He intends to feed Kawaki to the Ten-Tails in order to get the chakra fruit.
The suddenness of this move took everyone by surprise, and considering the bond between Boruto and Sasuke, it was a heartbreaking moment, to say the least. Fans have become used to Sasuke's insane strength stemming from his Rinnegan, and its loss marks the end of an era.