Board Thread:Theories and Speculation/@comment-26422040-20150725154528/@comment-26567684-20150822033041

They technically weren't good; they're just loyal to Sasuke, and when he decided to join forces with the Allied Shinobi Forces and fight against Madara, Orochimaru and Taka agreed to go with him to help him. Their alliance with the others was only temporary in order to stop the war.