Board Thread:Versus Debates/@comment-46828725-20200910033310/@comment-46974447-20200924204905

They can program the Sharingan to activate a certain ability if they know something like it WILL or COULD happen. Programming Izanagi to go off in the case of death is realistic because, at some point, everyone dies. Programming Amaterasu into Sasuke's eye was also plausible because Itachi knew sooner or later Obito would approach him. What would they even program their Sharingan to do? And yes, suppress and complete control are totally different things, but I don't think that was quite the point. The point was that controlling Kurama against another Uchiha with Sharingan, let alone MS, is foolish because that control can be fought over, and possibly, stolen.