Board Thread:Versus Debates/@comment-44916514-20200123204114/@comment-9782468-20200208165210

Jason of the Mangekyou wrote: The crow reacting to Itachi's MS would make more sense fr, but it doesn't explain how it would work on Sasuke who doesn't have the exact design only, as Itachi ,who would have no way of knowing what Sasuke's MS or EMS would look would not make sense for him to set the crow to react to just his mangekyou.....

It doesn't need the exact design, and that's already been proven. Their Sharingan have identifying features beyond just the visible outward design. And sealed jutsu can be coded to react only to certain Sharingan. If it's the case with Sharingan, it's easily the case with Mangekyo, since we know all Sharingan look the same.