The following contains spoilers for Chapter 1 of Naruto: Sasuke's Story -- The Uchiha and the Heavenly Stardust, by Masashi Kishimoto, Jun Esaka, Shingo Kimura, and Snir Aharon, now available in English from Viz Media.
In the Naruto and Boruto lore, it's safe to say that as good as Uchiha Sasuke is, he's had quite the torrid time fighting off the Ōtsutsuki clan. The aliens have been very formidable, which is why it took Sasuke and Naruto in their god modes -- as well as Sakura -- to defeat Kaguya. In time, they'd all have to unite and use the likes of Boruto in subsequent wars against Momoshiki, Kinshiki, Toneri, Urashiki and recently, Isshiki.
This is why Sasuke's main job as a Konoha Ranger is to keep prowling to ensure they never return, whether through Code, or the DNA in Boruto and Kawaki. Unfortunately, in his spinoff manga, Naruto: Sasuke's Story -- The Uchiha and the Heavenly Stardust, Sasuke is reminded there are other massive threats even more dangerous than the Ōtsutsuki beings.
Sasuke Struggles Against Menō in Heavenly Stardust
In Heavenly Stardust, Sasuke has infiltrated a prison in Redaku, hoping to find a cure for a mysterious illness Naruto's suffering from. However, he's shocked to learn there's a velociraptor outside the walls, acting as an enforcer. It loves devouring escapees, but Sasuke doesn't get distracted, sneaking out of his cell to gather data from the warden's office.
However, he runs into major trouble in the hallway when the dino, Menō, ambushes him. He couldn't sense it, plus it moves lightning-quick, which already handicaps Sasuke. He's never faced an enemy like this, made worse by his eyes not working on the being. Sasuke tries to use his Sharingan to slow it down and probe its mind, but not even his dream-inducing genjutsu works.
It's a crucial turning point as all these tools are what allowed Sasuke to fight back against tyrants like the Ōtsutsuki, but he has no advantage here. He's forced to use an ice kunai, cut its claws off and flee. The big shocker, though, is that he spots it in the yard the next day, healed up and looking for revenge with regenerated claws. It's clearly treating Sasuke as prey, which shapes a predator the Uchiha Ranger is left scrambling to re-strategize against.
Sasuke's New Orochimaru Is Even Scarier
The warden Sasuke is trying to garner intel from is Zansūru, who cuts an evil scientist figure much like Orochimaru from back in the day. Shockingly, Zansūru also sneaks up on Sasuke watching his pet dino the next morning, making it clear he knows Sasuke attacked the creature and is scurrying around the place. But Zansūru isn't intimidated at all, not even when Sasuke tries his Sharingan on him.
In fact, he laughs it off -- impervious and unmoved. That's because Zansūru has glass eyes, which means -- along with potential genetic tampering, as Sasuke suspects -- the overlord and Menō are invulnerable thus far. Some might say Sasuke is holding back to keep his cover, and once he applies other forms of ninjutsu and combat techniques, he can take them down. But no one knows what other secrets these enemies have that could neutralize the Ranger, which he has sensed already.
He might even be poisoned from the food and water, as Zansūru has been watching him for some time, coming off like a puppet master. Ultimately, this makes Heavenly Stardust's Zansūru better than Naruto's past villains because he's not about ego. More so, he loves operating in secret, shaping him and his raptor as unpredictable foes that could truly challenge Sasuke's mind.