The Hebi are Sasuke’s rogue ninja group, designated as threats all throughout the world. But why does Sasuke assemble a team?
Sasuke has to assemble a team so he can track down his brother, Itachi. He betrayed Orochimaru and gathered a team of shinobi in order to speed up the process of finding Itachi and finally fighting him.
The team is made up of two aggressive ninja to act as physical support and a sensory-type for reconnaissance. Karin, their sensory ninja, can also provide medical aid with her special ability.
Sasuke assembles and names his team
In chapter #348, Sasuke and Suigetsu are heading to Orochimaru’s prison after breaking free of his compound. Sasuke wants Karin, the prison warden, to join their team next.
Suigetsku asks Sasuke why he’s dragging a team together.
“I have a goal,” Sasuke says. “And a small team will let me reach that goal faster.”
Sasuke goes on to explain that he’s kept an eye out for exceptional and strong shinobi ever since he linked up with Orochimaru. He knew that one day he’d betray him and form his own group.
Suigetsku says that Sasuke could do better than Karin. She experimented on Suigetsku, and she’s a true believer of Orochimaru’s messages. Sasuke says although there are shinobi who are just as strong and easier to handle, Karin has a special ability that nobody else possesses. Karin is able to bite Sasuke and give some of her chakra to him at any given time.
Later, in chapter #352, Sasuke’s team is together and ready to move out for the first time. He declares their team shall be called “The Hebi,” and their only goal is reaching Itachi Uchiha.
So that’s the answer. Sasuke has to assemble a team because he wants help tracking down Itachi. Having some extra muscle as well as support while he searches for Itachi will speed up the process and prove useful.