As we all remember, Obito had around 50-100 sharingans stocked in his lab. He can use "true" Izanagi, and the right half of his body is made from Hashirama's cells.
So the question is: why couldn't Obito do the same thing that Danzo did: implanting sharingans in the right arm? Besides, since Obito possesses both Uchiha and Senju DNA, his version of Izanagi would be complete, unlike Danzo's.
Kamui + 10 Izanagi = "kill me if you can"
My guess is that it's either for plot sake ( I lean to this ) or Obito simply didn't have enough surgery skills. ( doubtful, I think he was slightly inferior to Orochimaru and Kabuto )
So the question is: why couldn't Obito do the same thing that Danzo did: implanting sharingans in the right arm? Besides, since Obito possesses both Uchiha and Senju DNA, his version of Izanagi would be complete, unlike Danzo's.
Kamui + 10 Izanagi = "kill me if you can"
My guess is that it's either for plot sake ( I lean to this ) or Obito simply didn't have enough surgery skills. ( doubtful, I think he was slightly inferior to Orochimaru and Kabuto )