As per my understanding, Izanagi permanently blinds the Sharingan's vision once used. Tobi (Obito) donated one eye to Kakashi, and used Izanagi with the other eye to escape from Konan's paper bombs. This means he should only have a Rinnegan now, but why does he still have a Sharingan with Kamui ability?
Note: I do not read manga.
Tobi assisted Itachi in the Uchiha clan massacre, and collected several Sharingan eyes of the dead Uchiha clan members. He must have implanted one of these Sharingan eyes in his left eye socket.
During the battle with Konan, he has two Sharingan eyes. He did not use his original right eye for the Izanagi, but the left eye, which can be seen "losing its light" (closing) as he is talking to Konan. See images below (taken from Chapter 510).
Tobi has a laboratory containing collection of sharingans, hence he could have implanted sharingan of someone else to himself.
I don't read manga, but here is my theory.
We know, as mentioned above, that Tobi/Obito didn't use his original sharingan for Izanagi but instead he used the Sharingan of the left eye. This may have been the Sharingan of Shisui.
I conclude this, because after Saskuke defeted Danzo, Tobi used Kamui and kept Danzo's body with him, saying he has something to do with.
@Happy Sorry, but I have to disagree with your answer.
Izanagi is an ability that will blind the caster.
However, those who posses the senju DNA can cast is again and again and again.
Source: When danzo was fighting sasuke, he used Izanagi. The eyes in his arm were shutting down one by one.
Yes those eyes were getting blinded, but not permanently.
If you posses the senju DNA you would be able to reuse Izanagi within a day time, i.e. the sharingan eyes will open again in a day time.
I am not confusing with the koto amatsukami.
I guess that partly answers your question.
