Excuse me ? Ludicrous ? You are the pinnacle of all idiots on this website . I clearly said it was a "thought". And clearly it's a possibility ..
Combo breaker. Exactly, as there is no definite proof that can counter OT, this is a good possibility.
Of course, a lot of people here have valid arguments as well, that talks about chakra exhaustion, and Kakashi having low chakra reserves. But people, we should remember Kakashi has many years training the proper use of the Sharingan. It wouldn't be so 'easy' for him to die of exhaustion.
Now, what really worries me is the fact that Kakashi must cover the eye with sharingan to stop using it. If Kakashi gets the other Kamui Sharingan, he won't be able to see.