Board Thread:Versus Debates/@comment-37960523-20190522205733/@comment-32685487-20190531222740

Itachi told him multiple times during the fight and before he revealed his Izanami plan kill Kabuto, so despite seeing what Kabuto was capable of during the fight he thought Sasuke could kill him. The senjutsu sound genjutsu and the White Rage tech are the only things Kabuto had that could legitimately pose a threat to Sasuke so if Kabuto can land those two in the right order and way then he can kill Sasuke, otherwise Sasuke will kill him.