Board Thread:Naruto Discussions/@comment-25139119-20140705022956/@comment-26302001-20140814103934

The "Straight Tomoe" is talking about the Center Mangekyo form that he attained from his EMS, so technically Itachi was the original owner of a Straight Tomoe MS, same with Izuna. So back at the VotE he only had a normal sharingan.. Izuna and Itachi were most likely linked somehow as they were both the brothers of the incarnates and they were both very powerful, Izuna being as strong as Madara and Itachi being stronger than Sasuke and most likely as strong as Izuna(because Sasuke is only a teen)