I'm pretty sure the first one to hit the other with his would win. Take Kabuto for example. Itachi trapped him in his Izanami, but no matter what he did or what he used, it didn't change a thing, since Itachi was in complete control at that time.
remember kabuto
Then..What if it happened simultaneously ??You must be registered for see links
Err..LOL? hahKabuto is an Uchiha then?
then it will be (izanami)[SUP]2[/SUP]... then it will require a 3rd uchiha to get them out of that loop...maybe by hitting really hard on their head they can get out of the loop...![]()