WARNING: The following contains major spoilers for Boruto: Naruto Next Generations #35, on sale now.
Following the end of the Naruto series, Sasuke was treated like a peripheral character. In the Boruto movie, he did get some fight time with Naruto against Momoshiki and Kinshiki, but the Boruto anime and manga just haven't given him his due in the limelight as a ranger patrolling the outskirts of Konoha.
Sure, we've seen him training Boruto and being in the village with his family, Sakura and Sarada, but fans wanted to see more of his special missions roaming around to protect the new ninja world order. The wait has now come to an end, however, because in Boruto #35, we find out his most important mission to date will be, and it involves Konoha's deadliest enemy.
With Naruto as Hokage, running the village, it's been known for some time Sasuke is on a mysterious beat of importance, especially with the new terrorist group, Kara, rearing its head. Using intel gathered by Naruto's understudy, Konohamaru, it's discovered the dangerous Ōtsutsuki clan have a temple hidden in a dimension which only space-time manipulators can find.
Cue Sasuke who, as a member of the Uchiha clan with ocular powers, can create portals to find these places. It's how he and Naruto chased Kaguya, the Ōtsutsuki villain who tried to destroy Earth at the end of Naruto: Shippuden. Basically, it allows Sasuke to go anywhere, anytime -- once he has initial data to start off with. Using the Rinnegan and the Sharingan eye abilities, he's mastered this art of teleportation and so, he creates a rift to locate this temple.
Shockingly, he doesn't like what he finds because it paints the coming of the Ōtsutsuki clan once more. In the past, after battling Kaguya, he and Naruto fought Momoshiki and Kinshiki, and Naruto also had to battle Toneri on the moon for Hinata's hand. Sasuke realizes this alien clan, who hail from an unknown dimension, have been invading Earth over the centuries in pairs, and with one pair down, according to sigils carved into the temple's mountain, two remain. Kaguya is dead, which leaves Sasuke to wonder who the next hologram is.
The answer to this is most likely Jigen, Kara's leader, who Sasuke actually spots sucking up energy from a very powerful monster in the temple, similar to how Kaguya fed off the God Tree when she went into full-on destroyer mode. What scares Sasuke even more is that he sees the final pair of sigils scratched off, so he doesn't know if that pair died, if they left Earth and are planning to return, or if they turned on their clan.
With Jigen levelling up so much, Sasuke has no clue if both he and Naruto will be able to tackle the warrior when the eventual showdown comes.
This is the first time we see the master shinobi sweating bullets: He knows this clan pushed him and his allies to their limits previously, so the fear is writ large on him. Earth barely survived the aliens' previous incursions and he must now find a way back to Naruto without getting caught by Jigen.
Sasuke has been very strategic when it comes to protecting Konoha in his role as a kind of black-ops agent. From the looks of this, the thought of him actually trying to find the Ōtsutsuki's world to strike first might be the next logical mission. He of all people knows when to go on the offensive and, with the stakes raised so high, Sasuke might not obey Naruto's orders if they don't match his vision.
The former antihero recognizes when a more aggressive approach is needed, and it looks like his journey is about to take an even darker turn as he formulates a plot to save mankind yet again.
Boruto #36 goes on sale July 21.