Why Sasuke Uchiha joins Akatsuki?
After his fight with Itachi he discovers that it was Konoha who had Itachi kill his family and clan and then leave Konoha. Itachi kept him alive though and said if he was ever killed Itachi would come and destroy Konoha. After Sasuke heard this, how his brother kept him alive and loved him he decided to go after Konoha for revenge, Madara asked him to join Akatsuki as he could help do it. So yeah, Sasuke is a villain, He always has been since he left Konoha.
