Naruto Gaiden 7 reveals Karin to be Sarada’s real mother, this is done by the help of Suigetsu who tested Karin’s DNA and Sarada’s DNA to see that they have a match. Sasuke suspects that Shin Uchiha is an experiment by Orochimaru, they head towards his hideout to find him to have a new body and explains who Shin is in terms of his past experiments.
Naruto Gaiden 6 shows Shin vs Sasuke as they both fight head to head in order to protect Sarada from any hard. Sasuke uses his ability against Shin and the kid, while Shin also uses his own Mangekyou Sharingan against Naruto and Sasuke to stab him. Sakura appears and smashes Shin into the ground, they disappear using Time-Space Technique.