Rate the strongest Kamui users
1. Juubi jin Madara Kamui/Rinnegan
Genius who surpassed Obito in one panel time. He's the only Juubi jin who could Kamui freely. He can sit in the Kamui world while his limbo clones do the job.
2. Obito Kamui/Rinnegan - He's just above Kakashi who proved to be a worthy opponent. I think healthy double MS is stronger than Rinnegan form, because obviously Obito cant unlock Rinnegans true potential, as he openly admitted it was too much for him to handle. But we cant include Double MS, because we have not seen Obito in a healthy state yet, nor do we have any feats of double Kamui so for now we just have to deal with the Rinnegan form.
3. Kakashi Kamui - He's the weakest out of 3, but clearly a shinobi who shouldnt be understimated. He did push Obito to the limits, so he's not that far behind as far as Obito goes.
4. Black Zetsu - Hasnt shown anything spectacular with Kamui, just some oridinary teleporting, so he's last on my list.