Complex sentence: Sasuke, unwilling to give himself up to a weakened Orochimaru, fights the attempted body-switch before using his Sharingan to void the jutsu and trap Orochimaru's soul in himself, giving him access to many of Orochimaru's abilities in the process.
Split into simpler sentences: Sasuke, unwilling to give himself up to a weakened Orochimaru, fights the attempted body-switch. Using the Sharingan to void Orochimaru's technique, Sasuke retains control of his body while trapping Orochimaru's soul within him, giving him access to many of Orochimaru's abilities in the process.