Originally Posted by a3jay14
Tobi never mentioned that he also wanted to massacre the uchiha clan since they "betrayed" him, he never told his involvement.
Yeah he did. Tobi flat out told Sasuke that he helped murder the clan along with Itachi. Sasuke already knew that anyway because he figured out that Itachi couldn't have done the job alone and Itachi confirmed it was Madara who helped him.